Yes, sharp is a Scrabble word!

Adverb

1. Changing suddenly in direction and degree

Adjective

1. (of something seen or heard) clearly defined

2. Ending in a sharp point

3. Having or demonstrating ability to recognize or draw fine distinctions

4. Marked by practical hardheaded intelligence

5. Harsh

6. Having or emitting a high-pitched and sharp tone or tones

7. Extremely steep

8. Keenly and painfully felt; as if caused by a sharp edge or point

9. Having or made by a thin edge or sharp point; suitable for cutting or piercing

10. (of a musical note) raised in pitch by one chromatic semitone

11. Very sudden and in great amount or degree

12. Quick and forceful

Noun

1. A musical notation indicating one half step higher than the note named

2. A long thin sewing needle with a sharp point