Possibly weariest, so to speak (2,2,4)
I believe the answer is:
as it were
'so to speak' is the definition.
(synonyms)
'possibly weariest' is the wordplay.
'possibly' indicates an anagram.
'weariest' anagrammed gives 'AS IT WERE'.
(Other definitions for as it were that I've seen before include "Seemingly" , "you may say" , "As if it was actually so" , "In a kind of way" , "So to speak" .)