Lean the wrong way, drop a catch (7)
I believe the answer is:
pitfall
'a catch' is the definition.
(thesaurus)
'lean the wrong way drop' is the wordplay.
'lean' becomes 'tip' (synonyms).
'the wrong way' says the letters should be written backwards.
'drop' becomes 'fall' (synonyms).
'tip' written backwards gives 'pit'.
'pit'+'fall'='PITFALL'
(Other definitions for pitfall that I've seen before include "Hidden danger or difficulty" , "Unexpected problem" , "Trap in the form of a concealed hole" , "Unsuspected danger or difficulty - for miner?" , "Unexpected difficulty or danger" .)