Month sees pair in trouble (5)
I believe the answer is:
april
'month' is the definition.
(I know this)
'pair in trouble' is the wordplay.
'pair' becomes 'pr' (abbreviation).
'in' is an insertion indicator.
'trouble' becomes 'ail' (synonyms).
'pr' going within 'ail' is 'APRIL'.
'sees' is the link.
(Other definitions for april that I've seen before include "First month of the year with 30 days" , "Fourth month" , "4th month" , "All in the ..... evening (song)" , "''... is the cruellest month''(Elliot)" .)