Slack, the red hot $3.8 billion startup, has a hidden meaning behind its name

Slack is a super popular business app startup that's grown to be worth $3.8 billion in just a little over two years since its official launch.

But not many people know the actual meaning behind the company's name, Slack.

Some people guessed it's supposed to stand for the term used in project management, which refers to the "amount of time a delay could take from a task without causing subsequent problems."

But according to Slack CEO Stewart Butterfield, Slack is actually an acronym. It stands for: Searchable Log of All Conversation and Knowledge.

That's exactly what Slack is, although most people use it for chatting and sharing links and files, and don't worry about the searchability so much.

Butterfield shared this through a Twitter conversation he had with someone who asked about the name's origin. He also notes Slack's original codename used to be "linefeed."

Slack joins at least one other prominent tech company whose name is an acronym: Yahoo, which originally stood for "Yet Another Hierarchical Officious Oracle," a joking reference to its original product, a web directory.