Backronym (also bacronym) (noun)
bak-ron-im
An acronym deliberately formed from a phrase whose initial letters spell out a particular word or words, either to create a memorable name or as a fanciful explanation of a word’s origin.
1980s blend of back and acronym.
Example sentences
“”America’s Missing: Broadcast Emergency Response”, which spells out AMBER, is one of the best known backronyms today.”