Temper can refer to a tendency to become unreasonably angry. If you’re not sure whether you have a temper, ask your friends — but don’t get mad if you dislike what they have to say.
Temper has a number of related yet distinct meanings. In addition to describing a tendency to anger, temper can also refer to one’s mood in general; if you use the word in this sense, you might describe someone's temper as "angry" or "mild." Temper can also be used as a verb meaning “to restrain.” If you have a nasty temper, you might try tempering your temper by counting to ten whenever you’re tempted to throw a "temper tantrum," or fit.