Yes, boss is a Scrabble word!

Verb

1. Raise in a relief

Adjective

1. Exceptionally good

Noun

1. A person who exercises control over workers

2. A person responsible for hiring workers

3. A person who exercises control and makes decisions

4. A leader in a political party who controls votes and dictates appointments

5. A circular rounded projection or protuberance

6. Wild and domestic cattle; in some classifications placed in the subfamily Bovinae or tribe Bovini