What part of speech is fictionalize?

Fictionalize can be categorized as a verb.

Parts of speech

1. fictionalize is a verb, present, 1st person singular of fictionalize (infinitive).
2. fictionalize is a verb (infinitive).

Verb
fictionalize - make into fiction; "The writer fictionalized the lives of his parents in his latest novel"
fictionalize - convert into the form or the style of a novel; "The author novelized the historical event"