Lift in holiday centre going the wrong way, uncle's head stuck in it (7)
I believe the answer is:
trouser
'lift' is the definition.
(both can mean to steal)
'holiday centre going the wrong way uncle's head stuck in it' is the wordplay.
'holiday centre' becomes 'resort' (a holiday resort).
'going the wrong way' shows that the letters should be reversed in order.
'head' indicates taking the first letters.
'stuck in it' indicates putting letters inside.
The first letter of 'uncles' is 'u'.
'resort' written backwards gives 'troser'.
'troser' going around 'u' is 'TROUSER'.
'in' is the link.
(Other definitions for trouser that I've seen before include "Pocket (something)" , "For oneself" , "Pocket (slang)" , "Our rest (anag)" , "Appropriate" .)