Respondent

Part of speech: noun (n.)

1. One who responds. It corresponds in general to defendant. Specifically:

2. One who maintains a thesis in reply, and whose province it is to refute objections, or overthrow arguments; -- distinguished from opponent. I. Watts.

Part of speech: adjective (a.)

Disposed or expected to respond; answering; according; corresponding. Wealth respondent to payment and contributions. Bacon.