The answers to the clues below will have something in common.

1. Refuse to talk
2. Lawn invader
3. Restaurant, hotel counter specialty
4. Tasty appetizer
5. Musical composition for five by Franz Schubert

Answers:

1. Clam up
2. Crabgrass
3. Oyster bar
4. Shrimp cocktail
5. Trout Quintet