Identify a bell incorrectly (5)
I believe the answer is:
label
'identify' is the definition.
(I know that label is a more specific form of the action differentiate)
'a bell incorrectly' is the wordplay.
'incorrectly' indicates anagramming the letters (I've seen this in other clues).
'a'+'bell'='abell'
'abell' with letters rearranged gives 'LABEL'.
(Other definitions for label that I've seen before include "Identifying tag" , "Identity tag" , "Classifying name" , "Tag; record company" , "Name-tag" .)