It’s an adjective and it means not having or lacking enthusiasm. If someone is unenthusiastic about something it means they are feeling indifferent, apathetic, passive, phlegmatic, lukewarm, listless, languid, lethargic, emotionless, perfunctory about it.
I’m unenthusiastic about having Malcolm on the team.
lacking giving a shit, such as the difference between taking home your ex and taking home a new girl. Can also be used in many situations involving boredom and mundane activities.
You seem a little unthusiastic about helping me clean out my basement.
Your obvious unthusiasm tells me you'd rathher pork that girl than go home with me again.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi
May I have an order of regular degular buttermilk pancakes? Without all the added jazz? Hold the blueberry smiley face, strawberry glaze, chocolate chips and whipped cream.