Agent
来自Big Physics
late Middle English (in the sense ‘someone or something that produces an effect’): from Latin agent- ‘doing’, from agere .
wiktionary
From Latin agēns, present active participle of agere(“to drive, lead, conduct, manage, perform, do”).
etymonline
agent (n.)
late 15c., "one who acts," from Latin agentem (nominative agens) "effective, powerful," present participle of agere "to set in motion, drive forward; to do, perform; keep in movement" (from PIE root *ag- "to drive, draw out or forth, move"). Meaning "any natural force or substance which produces a phenomenon" is from 1550s. Meaning "deputy, representative" is from 1590s. Sense of "spy, secret agent" is attested by 1916.
agent (adj.)
1610s, from agent (n.).
