IPA: /ɪnˌtɛrəˈɡeɪ/
KK: /ɪnˌtɛrəˈɡiː/
A person who is being questioned or examined, especially in a formal or official setting.
The interrogatee remained calm during the questioning.
Interrogatee is formed from "inter-" (meaning between) and "rogare" (meaning to ask). The term refers to a person who is being asked questions, typically in a formal or legal context, thus indicating someone caught in the act of questioning between the interrogator and themselves.
Think of someone being 'asked' ('rogare') questions 'between' ('inter-') the interrogator and themselves — that's what an interrogatee is.