Yearn for a try in the past (4,3)
I believe the answer is:
long ago
'in the past' is the definition.
(I've seen this before)
'yearn for a try' is the wordplay.
'yearn' becomes 'long-' (synonyms).
'for' is a charade indicator (letters next to each other).
'try' becomes 'go' (both can mean an attempt).
'long'+'a'+'go'='LONG-AGO'
(Other definitions for long ago that I've seen before include "In times gone by" , "Remote in time" , "way back" , "Very far back in time" , "in the 26 [PAST]" .)