backronym:
A backronym, or bacronym, is a specially constructed phrase that is supposed to be the source of a word that is, or is claimed to be, an acronym. Backronyms may be invented with serious or humorous intent or may be a type of false etymology or folk etymology. [Wikipedia]
Noted in “Meet the Next-Generation Space Telescope,” Korey Haynes, Discover, July / August 2017 (offline only?):
HDST is only one placeholder name for this project. A previous NASA study used the wistful backronym ATLAST, which has come to stand for Advanced Technology Large-Aperture Space Telescope.
