The crossword solution for the term MERMAIDS CO-STAR is CHER, a four letter word. Cher is an American singer, actress, and television personality who rose to fame in 1965 as part of the folk rock duo Sonny & Cher. She has since become a successful solo artist, winning an Academy Award for Best Actress for her role in Moonstruck in 1988. In 1984, she starred alongside Daryl Hannah and Eric Stoltz in the movie Mermaids, playing the mother of Hannah's character.