Hot on ex, I’m unable to drink (10)
I believe the answer is:
intoxicant
'drink' is the definition.
(I know that intoxicant is a type of drink)
'hot on ex i'm unable to' is the wordplay.
'hot' becomes 'in' (both can mean fashionable).
'on' means one lot of letters goes inside another (as in clothing 'on' a person).
'ex' becomes 'x'.
'i'm' becomes 'toi' (I am not sure about this - if you are sure you should believe this answer much more).
'unable to' becomes 'cant' (I've seen this in another clue).
'x' inserted within 'toi' is 'toxi'.
'in'+'toxi'+'cant'='INTOXICANT'
Can you help me to learn more?
(Other definitions for intoxicant that I've seen before include "eg Alcoholic drink" , "Something like alcohol" .)