"Here's a knocking indeed! If a man were porter of hell-gate, he should have old turning the key.
Knock, knock, knock! Who's there, i' the name of Beelzebub?"
How Shakespeare uses it: There's no direct connection from Macbeth to the knock-knock joke, but it is fun that a phrase that we now associate with lame-ish jokes is also found in the scene after Macbeth murders Duncan.
"...But love is blind and lovers cannot see The pretty follies that themselves commit;..."
How Shakespeare uses it: Technically, Chaucer first wrote the phrase "For loue is blynd alday and may nat see." But Shakespeare was the one who popularized it.
In the scene, Jessica has disguised herself as a boy to see her lover, Lorenzo, but feels quite "ashamed" of her get-up. Still, she comments that love is blind and people are unable to see the shortcomings of their lovers.
Modern definition:The meaning of the phrase is more or less unchanged.
The Prince of Morocco, one of Portia's suitors in "The Merchant of Venice," much choose out the correct casket to get his bride: one gold, one silver, and one lead. The gold one has an inscription on it which reads "All that glitters is not gold ... gilded tombs do worms enfold." But he picks it anyway ...
Modern definition:Basically, just because it's shiny and nice on the outside, doesn't mean that that's true of the inside.
Rosalind is pretending to be a man named Ganymede while she is with Orlando, with whom she is in love. He's also in love with Rosalind — and doesn't know she is Ganymede — and practices how he would woo Rosalind with Ganymede. At one point, Rosalind/Ganymede suggests that they have a pretend wedding, and asks if one can ever have too much of a good thing.
Modern definition: Too much good might backfire and be bad.
"Give me that man That is not passion's slave, and I will wear him In my heart's core, ay, in my heart of heart, As I do thee."
How Shakespeare uses it: While speaking with Horatio, Hamlet says this phrase noting that if there's a man who is "not passion's slave" — aka, a master of his emotions — then he'll put him close to his heart. Using the language "heart's core" right before suggests that Hamlet means some very deep, central part of his heart/emotions.
Modern definition: Nowadays, we pluralize the second "heart" to say "in my heart of hearts." The phrase refers to one's inner-most, secret thoughts.
"Thou hast spoken right, 'tis true; The wheel has come full circle: I am here."
How Shakespeare uses it: Edmund says the phrase at the end of "King Lear," highlighting how he has "completed a cycle" where his diabolical actions have come back to haunt him.
Shakespeare was also probably referencing Fate — and the "Wheel of Fortune" — from ancient and medieval philosophy, which thus introduced the question of free will versus everything being determined by fate.
Modern definition: Completing a cycling, getting back to the beginning.
"We are such stuff As dreams are made on, and our little life Is rounded with a sleep."
How Shakespeare uses it: This phrase is not as cheerful as we use it today. Prospero is saying that peoples' lives — and his magic — are like dreams: We experience them, and then they totally evaporate without leaving any lasting evidence. "Sleep" likely refers to death here.
Modern definition: Nowadays, we say "stuff that dreams are made of" rather than "on." And it also refers to some sort of fantasy things or life that we could only dream of having.
"O worthy Goth, this is the incarnate devil That robb'd Andronicus of his good hand." (Titus Andronicus)
"Yes, that a' did; and said they were devils incarnate." (Henry V)
How Shakespeare uses it: Lucius calls Aaron the Moor the "devil incarnate" — aka a devil in the flesh — after all the suffering he causes his family. Chief among them, convincing Demtrius and Chiron to rape Lavinia and framing Martius and Quintus for the murder of Bassianus.
Shakespeare also reused the phrase about a decade later in "Henry V."
Modern definition: The meaning of the phrase is more or less unchanged.
"The king's a bawcock, and a heart of gold, A lad of life, an imp of fame; Of parents good, of fist most valiant. ..."
How Shakespeare uses it: King Henry disguises himself as a commoner in the play and asks Pistol, who is unaware of the disguise, whether he considers himself to be better than the king. Pistol responds with the above quote.
Modern definition: To be extremely kind and helpful.
"I pray, sir, tell me, is it possible That love should of a sodaine take such hold?"
How Shakespeare uses it: Apparently, Shakespeare might have thought that "all of a sudden" was a more poetic way of saying "suddenly" so he had the character Tranio in "The Taming of the Shrew" say it that way.
Although, Shakespeare wasn't the first to use "sudden" — John Greenwood used it in 1590.
Modern definition: The meaning is the same, although we now spell it "sudden" rather than "sodaine." The word is spelled in the modern way in newer printings of "The Taming of the Shrew."
"What hempen home-spuns have we swaggering here, So near the cradle of the fairy queen? What, a play toward! I'll be the auditor; An actor too, perhaps, if I see cause."
How Shakespeare uses it: Puck, a mischievous sprite, uses the term "swagger" to mean "insolent." It might have been a frequentative form of "swag," which means "to sway."
The word is also found in "Henry IV: Part 2" where Mistress Quickly gives a speech about super-aggressive men who visit her tavern, where the meaning of swagger suggests the meaning of boasting or bragging.
Additionally, the term is also found in "King Lear," where it most closely means "blustering." Although, here it is spelled "zwaggered."
Modern definition: Jay Z used "swagger" and "swag" in several songs back in the early 2000s. Soulja Boy also used the word — "she likes my swag." Since then, it has been often used in modern song lyrics.
"For when my outward action doth demonstrate The native act and figure of my heart In compliment extern, 'tis not long after But I will wear my heart upon my sleeve For daws to peck at: I am not what I am."
How Shakespeare uses it: Devious Iago basically says that if his outward appearance reflected what he was thinking, then his heart would be on his sleeve for birds to peck at — which is not a good idea in his eyes. And so he adds that he is actually not what he appears to be.
Notably, Iago's motives for his antagonistic behavior are never fully revealed — so it is interesting that he is the character who has immortalized this phrase.
"... And if you break the ice and do this feat, Achieve the elder, set the younger free For our access, whose hap shall be to have her Will not so graceless be to be ingrate."
How Shakespeare uses it: Tranio suggests if Petruchio can "break the ice," then he will be able to woo Katherina. By using the "ice" language, Shakespeare makes Katherina seem as cold as ice. Moreover, the fact that the ice needs to be broken suggests that she is hard to reach.
"Oh, beware, my lord, of jealousy! It is the green-eyed monster which doth mock The meat it feeds on."
How Shakespeare uses it: Iago says this phrase as he plants doubts in Othello's mind about his wife's faithfulness. Merriam-Webster writes that he may have been evoking cats, given that they are "green-eyed creatures who toy with their prey before killing it."
Modern definition: Now "the green eyed-monster" is an idiomatic expression for the noun "jealousy."
"Then put up your pipes in your bag, for I'll away. Go; vanish into air; away!" (Othello)
How Shakespeare uses it: The Clown says this to the musicians in "Othello" to make them go away.
But some have also suggested that there is a darker underlying meaning. Act 3 in Othello is the final act that suggests that all of this might have a happy ending. It gets pretty dark starting in Act 4. So the Clown might be symbolically asking musicians and all happy things to "vanish into thin air" because there's no more room for them in the play.
"All the world's a stage, And all the men and women merely players: They have their exits and their entrances; And one man in his time plays many parts, His acts being seven ages. At first the infant, Mewling and puking in the nurse's arms. ..."
How Shakespeare uses it: "Puking" was first recorded in Shakespeare's "As You Like It." It was likely an English imitation of the German word "spucken," which means to spit.
Modern definition: A synonym for the verb "to vomit."