Immoderate means not within reasonable and sensible limits — too much. You hear it of eating, drinking, spending, praise, or heat of feeling: immoderate drinking, immoderate demands, immoderate language. It is a rather bookish, slightly old-fashioned adjective; many people would just say 'too much' or 'excessive'. You meet it in essays and in moral talk more than in casual chat. It is not about fashion or being up to date. The calm opposite is moderate: within sensible limits. Though actually, calling someone's joy immoderate can sound a little scolding, as if even happiness should know when to stop.