Couple also outspoken (3)
I believe the answer is:
two
'couple' is the definition.
(two people or things)
'also outspoken' is the wordplay.
'also' becomes 'too' (synonyms).
'outspoken' indicates a 'sounds like' (homophone) clue (as the word might be spoken).
'too' sounds like 'TWO'.
(Other definitions for two that I've seen before include "not very many" , "1 + 1" , "A pair (3)" , "Cardinal number" , "Company, so it's said" .)