Why was "tantrum" trending last week?
from French assimilation of en- to following labial (see en- (1)). Also a prefix used to form verbs from adjectives and nouns.
representing Latin ex- assimilated to following -m- (see ex-).
Middle English, now taken as a colloquial abbreviation of them, but originally a form of hem, dative and accusative of the third person plural pronoun.
EM abbr. electron microscope
em- pref. Variant of en-2.
End of Medium