Yes, crab is a Scrabble word!

Verb

1. Direct (an aircraft) into a crosswind

2. Scurry sideways like a crab

3. Fish for crab

4. Complain

Noun

1. Decapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers

2. A quarrelsome grouch

3. (astrology) a person who is born while the sun is in Cancer

4. The fourth sign of the zodiac; the sun is in this sign from about June 21 to July 22

5. The edible flesh of any of various crabs

6. A louse that infests the pubic region of the human body

7. A stroke of the oar that either misses the water or digs too deeply