IPA: /ˌɪn.təˈpɛl.eɪ.tər/
KK: /ɪnˈtɜr.pə.leɪ.tər/
A person who questions or interrogates someone, especially in a formal or official context.
The interpellator asked the minister several challenging questions during the session.
Interpellator → It is formed from "inter-" (meaning between) and "pellere" (meaning to drive or push). The word refers to someone who drives or pushes between, often in the context of questioning or addressing someone directly.
Think of someone who 'drives' ('pellere') a question 'between' ('inter-') people — that's why interpellator means someone who questions or addresses others.
No commonly confused words.