c. 1300, respounse, "an answer, a reply," from Old French respons (Modern French réponse) and directly from Latin responsum "an answer," noun use of neuter past participle of respondere "respond, answer to, promise in return," from re- "back" (see re-) + spondere "to pledge" (see sponsor (n.)).
The transferred sense, of feelings or actions, is from 1815 in poetry and psychology. The meaning "a part of the liturgy said or sung by the congregation in reply to the priest" is by 1650s. Response time attested from 1958.
"very loud," 1590s, present-participle adjective from deafen (q.v.). Deafening silence "heavy and conspicuous silence," especially as a response to a question, is attested by 1830.
"repeat a response after the cessation of the original stimulus," by 1909, in psychology, a back-formation from perseveration. Related: Perseverating; perseverative.
1610s, "to give and return mutually," a back-formation from reciprocation, or else from Latin reciprocatus, past participle of reciprocare "rise and fall, move back and forth; reverse the motion of," from reciprocus "returning the same way, alternating" (see reciprocal). Sense of "cause to move back and forth" is from 1650s; intransitive sense of "move backward and forward" is from 1670s. Meaning "to give or do in response, act in return or response" is from 1820. Related: Reciprocated; reciprocating.