A mermaid is a mythical creature that is half woman and half fish. The name comes from 'mer' meaning sea. The male version is called a merman.
Although some mermaids are described as monstrous and ugly, they are more usually very beautiful. Above the waist they appear as a lovely young woman, whilst from the waist down, they are like a fish with fins and a spreading tail.
Mermaids like to comb their long hair. In art, they are often shown with a mirror and a comb. Sometimes they sit on a rock and sing, luring sailors to their destruction. This is why they are often confused with sirens (who also inhabit the sea). Mermaids lure handsome young men to their homes in the deep seas. Mermen, however, are usually wilder and uglier than mermaids and have little interest in humans.