Yes, up is a Scrabble word!

Adverb

1. Spatially or metaphorically from a lower to a higher position

2. To a higher intensity

3. Nearer to the speaker

4. To a more central or a more northerly place

5. To a later time

Adjective

1. Being or moving higher in position or greater in some value; being above a former position or level

2. Out of bed

3. Getting higher or more vigorous

4. Extending or moving toward a higher place

5. (usually followed by `on' or `for') in readiness

6. Open

7. (used of computers) operating properly

8. Used up

Verb

1. Raise