A deception you can see ahead? (3)
I believe the answer is:
con
'a deception' is the definition.
(a con is a trick or deception)
'you can see ahead?' is the wordplay.
I cannot quite understand how this works, but
'see' could be 'c' (the word for the letter, according to Chambers) and 'c' is found within the answer.
'ahead?' could be 'on' (synonyms) and 'on' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for con that I've seen before include "Direct steering; study" , "Trick, deceive" , "Deceive; convict (colloq.)" , "Tory" , "Informally swindle" .)