Lacking substance, accepting base trickery (7)
I believe the answer is:
sleight
'trickery' is the definition.
(as in sleight of hand)
'lacking substance accepting base' is the wordplay.
I cannot quite see how this works, but
'substance' could be 's' (S is an example) and 's' is located in the answer.
'base' could be 'e' (Euler's number - base of natural logarithms) and 'e' is found in the answer.
The remaining letters 'light' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sleight that I've seen before include "distraction?" , "Manual dexterity" , "Hits leg (anag) - cunning" , "Conjuror uses this" , "Handy skill" .)