Idealize is a verb.
Young children idealize their parents, by age 15 they know better.
"Idealize" is describing what some-one has done, so it would be probably an adjective.
Here is an example: Eminem is an ideal leader of hip-hop music
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
idealize
The verb is "idealise" ( or "idealize").
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.