questioner /
AmE ˈkwɛstʃ(ə)nər

,
BrE ˈkwɛstʃ(ə)nə
/ noun
1 (interrogator) interrogador m/interrogadora f;
(in Parliament, at meeting) interpelante mf she couldn't see her questioner no podía ver a quien le había hecho la pregunta
2 (doubting, challenging) contestatario m/contestataria f