Yes, ribs is a Scrabble word!

Verb

1. Form vertical ribs by knitting

2. Subject to laughter or ridicule

Noun

1. Support resembling the rib of an animal

2. Any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)

3. Cut of meat including one or more ribs

4. A teasing remark

5. A riblike supporting or strengthening part of an animal or plant

6. A projecting molding on the underside of a vault or ceiling; may be ornamental or structural