c. 1600, "subjugated," past-participle adjective from subdue. Meaning "calmed down, reduced in intensity" is recorded from 1822.
Entries linking to subdued
subdue v.
late 14c., "to conquer and reduce to subjection," from Old French souduire, but this meant "deceive, seduce," from Latin subducere "draw away, lead away, carry off; withdraw" (see subduce). The primary sense in English seems to have been taken in Anglo-French from Latin subdere and attached to this word. Related: Subdued; subduing. As an associated noun, subdual is attested from 1670s (subduction having acquired other senses).