IPA: /ˌɪn.təˈlɛk.tʃu.əl.ɪst/
KK: /ɪnˈtɛlɪktʃuəlɪst/
A person who supports or believes in the principles of intellectualism, which emphasizes the importance of intellect and reasoning.
As an intellectualist, she valued critical thinking and the pursuit of knowledge above all else.
Intellectualist is formed from "intellect" (from Latin "intellectus", meaning understanding or perception) and the suffix "-alist" (meaning one who practices or advocates). The word refers to a person who emphasizes or advocates for the importance of intellect and intellectual pursuits.
Think of someone who is an advocate for 'understanding' ('intellect') — that's what an intellectualist is.