Yes, duck is a Scrabble word!

Verb

1. To move (the head or body) quickly downwards or away

2. Submerge or plunge suddenly

3. Dip into a liquid

4. Avoid or try to avoid fulfilling, answering, or performing (duties, questions, or issues)

Noun

1. Small wild or domesticated web-footed broad-billed swimming bird usually having a depressed body and short legs

2. (cricket) a score of nothing by a batsman

3. Flesh of a duck (domestic or wild)

4. A heavy cotton fabric of plain weave; used for clothing and tents