All but, bit, bit, act, character, book, bit, be off, abandon, (up) to a point, and a little are all synonyms for part. Whole and entirety are these antonyms of part. And here are another 136 synonyms for part.
1. bit
2. component
3. section
4. role
5. ines
6. involvement
7. leave
8. give up
9. to a certain extent/degree