When you think of an acronym — such as NASA, RSVP or FOMO — you might think of exactly what you see in the examples we just shared: all capital letters. Or maybe periods come to mind.
While those are obvious markers, there are some acronyms lurking in our vocabulary that look just like regular words, written entirely in lowercase letters. For example, if you were going to try scuba diving this season, you probably wouldn’t write it as “SCUBA” or “S.C.U.B.A.” in your holiday letter.
But “scuba” is actually an acronym for “self-contained underwater breathing apparatus.”