Describes someone who changes moods or behaviors without warning, which can be challenging to deal with. My boss is rather temperamental; one minute he's happy, the next he's upset.
Pro Tip 2/3
Intense Reactions
Often implies strong, possibly over-the-top reactions or emotions. She's quite temperamental, crying at even the slightest criticism.
Pro Tip 3/3
Creative Stereotype
Commonly used to describe artists and creative individuals, suggesting sensitivity and passion. The temperamental poet refused to read his work in a room that wasn't silent.