The party being complained about in alternative dispute resolution proceedings (same as the defendant in court proceedings).
Merriam-Webster Online Dictionary
respondent (noun)1.
one who as - responds
a) one who maintains a thesis in reply
b) (1) one who answers in various legal proceedings (as in equity cases)
(2) the prevailing party in the lower court
c) a person who responds to a poll
2.
a reflex that occurs in to a specific external stimulus - response compare operant
1.
making - response responsive , especially being a respondent at law
2.
relating to or being behavior or to a stimulus that are followed by a reward - responses respondent conditioning compare operant 3
Respondent (Wikipedia)
A respondent is a person who is called upon to issue a response to a communication made by another. The term is used in legal contexts, in survey methodology, and in psychological conditioning.