An attempt to get past (3)
I believe the answer is:
ago
'past' is the definition.
(similar in meaning)
'an attempt' is the wordplay.
'an' becomes 'a'.
'attempt' becomes 'go' (go is a kind of attempt).
'a'+'go'='AGO'
'to get' acts as a link.
(Other definitions for ago that I've seen before include "Gone, past, since" , "(Years) before the present time" , "Previously" , "Time past" , "Back (in time)" .)