Easy street just ahead, having employed ace earlier (15)
I believe the answer is:
straightforward
'easy' is the definition.
(I've seen this before)
'street just ahead having employed ace earlier' is the wordplay.
I cannot really see how this works, but
'street' could be 'st' (abbreviation) and 'st' is found in the answer.
'ahead' could be 'forward' (synonyms) and 'forward' is present in the answer.
'ace' could be 'i' (synonyms) and 'i' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for straightforward that I've seen before include "Easy to understand" , "Clear" , "Honest, open" , "That's simple" , "Right on!" .)