Tear up about a couple (4)
I believe the answer is:
pair
'couple' is the definition.
(I know that couple can be written as pair)
'tear up about a' is the wordplay.
'tear' becomes 'rip' (synonyms).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'about' is an insertion indicator.
'rip' reversed gives 'pir'.
'pir' going around 'a' is 'PAIR'.
(Other definitions for pair that I've seen before include "Two of a kind, as in cards" , "E.g. two aces; mate" , "Brace, couple" , "2" , "Husband and wife" .)