Definitions:

1. all at the same time adverb
   • When we're all together at the family reunion, it's always a joyous occasion.
2. used of a group whose members acted or were acted upon collectively and when `all' and `together' can be separated by other words adverb
   • When we're all together at the family reunion, it's always a joyous occasion.

Synonyms:

• all at once