Speculative citizen swaps an ace for nothing (8)
I believe the answer is:
notional
'speculative' is the definition.
(I know that speculative can be written as notional)
'citizen swaps an ace for nothing' is the wordplay.
I cannot quite see how this works, but
'an' could be 'i' (Roman numeral for one) and 'i' is found within the answer.
'ace' could be 'a' (abbreviation) and 'a' is present in the answer.
'for' could be 'to' (eg both can mean 'in the opinion of') and 'to' is located in the remaining letters.
'nothing' could be 'no' (similar in meaning) and 'no' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for notional that I've seen before include "Assumed to be correct for particular purpose, say estimate" , "Hypothetical, assumed to be correct" , "La Gioconda" , "Like ideas of" , "Existing as theory, not existing in reality" .)