Run alongside end of terrace (3)
I believe the answer is:
bye
'run' is the definition.
(I've seen this before)
'alongside end of terrace' is the wordplay.
'alongside' becomes 'by' (I've seen this in other clues).
'end of' indicates one should take the final letters.
The final letter of 'terrace' is 'e'.
'by'+'e'='BYE'
(Other definitions for bye that I've seen before include "[ADIEU]" , "Extra run in cricket" , "Farewell! (informal)" , "Reason not to play" , "So long" .)