What does the cryptic crossword clue "This convention is full of people, say (4)" mean?

The definition is "This convention". The wordplay uses a homophone (sounds like). homophone/”say” of ‘packed’=”full of people” The answer is PACT.

This convention is full of people, say (4)

Guardian Cryptic #28708 | 1 Down | 2022-03-18 flower