A critic is someone who finds fault with something and expresses an unfavorable opinion. You might be a critic of your school’s new plan to start the school day at 6:30 a.m.
The word critic came into English by way of Latin, tracing back to the Greek word krinein, meaning “judge, decide.” If you’re a critic, you’re essentially judging something — and finding it lacking. Critic can be used broadly to describe any person expressing an unfavorable view, but there are professional critics as well, such as people who review movies or music. In that sense, the word describes someone who thoughtfully assesses something, either favorably or negatively.