A Portmanteau of the words mayonnaise and adolescent, also relates to the fact that teens love mayonnaise as a favorite condiment for foods, after ketchup of course. Just like how adults prefer mustard over mayo teens these days love mayonnaise, these days.
Person 1: Did you know that mayonnaise has the same number of letters as the word that describes a teenager?
Person 2: Yes, you mean "Adolescent", what about it?
Person 1: Well it just so happens that mayonnaise was voted the 2nd favorite condiment for hot dogs burgers and other foods among people aged 25 and younger, after ketchup that is.
Person 2: And your point is.............????????
Both together: Mayonescent!!! Yea exactly.......
Person 1 : What about mustard?
Person 2: Naw......Mustard sucks, everybody who is young hates it, nobody younger than 22 likes mustard these days, only old people eat that shit!
Person 1: Aight.