noun

1. something said or done in answer; reply or reaction
2. Eccles.
   1. a word or words used in replying to or affirming a prayer, reading, or exhortation
   2. responsory
3. Electronics the ratio of the output to the input, as for a given frequency, of a device or system operating under specified conditions
4. Physiol., Psychol. any biological reaction or behavior resulting from the application of a stimulus

Etymology: ME respounse < ML respons < L responsum, neut. of responsus, pp. of respondere: see respond