Histrionize, defined as "to behave theatrically or melodramatically," is a colorful word that may be unfamiliar to some. If you're looking to express the same meaning with different words, you might try using any of these synonyms: dramatize, overact, ham it up, emote, exaggerate, or be melodramatic. Other options include being theatrical, putting on an act, acting out, or playing a role. Depending on the context, you might also consider using words like perform, entertain, or command attention, as all of these can suggest an element of showmanship or attention-seeking behavior. Ultimately, the right synonym will depend on the specific tone and context of your writing or conversation.