acronym (n.) Look up acronym at
word formed from the first letters of a series of words, 1943, American English coinage from acro- + -onym "name" (abstracted from homonym; see name (n.)). With the exception of cabalistic esoterica and acrostic poetry, this way of forming words was exceedingly uncommon before 20c. For distinction of usage (regretfully ignored on this site), see initialism.