Groomer has several different meanings:

1. A person whose job is to make animals look neat and clean, especially dogs and horses. A dog groomer gives baths, trims fur, clips nails, and brushes out tangles. Professional groomers use special tools and techniques to help keep pets healthy and comfortable. Horse groomers brush coats, clean hooves, and braid manes for horse shows. Some groomers work in pet salons, while others travel to people's homes. A well-groomed dog has clean, shiny fur and trimmed nails.
2. Someone who takes care of their own appearance carefully. You might say that someone is “well-groomed” if their hair is neat, their clothes are clean and pressed, and they look put-together. Athletes and performers often need to be well-groomed for competitions or performances.
3. Important: In another meaning, a groomer is an adult who builds trust with a child to take advantage of them, especially in a sexual way. This is harmful and illegal. If you ever feel uncomfortable about how an adult is acting toward you or someone else, tell a trusted adult right away.

The verb form groom can also mean preparing something to look its best: you might groom your hair before school pictures or groom a hiking trail by clearing away branches and rocks.