I have a habit of using the phrase ‘Later Gator’ or the politically correct ‘Later Gatorette’ in emails/IM. Over the last couple months, I’ve been asked by a couple friends whose first language isn’t English to explain.
After a little searching on Google, I’ve found a suitable answer. It apparently comes from the Swing/Jazz era in the US:
Originally, a slang term for ‘Musician’. Very early in Jazz history, musicians referred to themselves as ‘alligators’. Now it simply refers to any Swing Devotee (abbrev. ‘Gator or Gate)
Note: Louis Armstrong is often called ‘Gate Mouth’, from the same source.
Ex: ‘Cat’ #1: See ya later, alligator.
Cat’ #2: After while, crocodile.”