turtle

(noun) a sweater or jersey with a high close-fitting collar. Synonyms: turtleneck, polo-neck.

(noun) any of various aquatic and land reptiles having a bony shell and flipper-like limbs for swimming.

(verb) overturn accidentally. Synonyms: capsize, turn turtle. Example: "Don't rock the boat or it will capsize!."

(verb) hunt for turtles, especially as an occupation.