Perhaps too haphazardly, it may be misplaced by shopkeeper? (10)
I believe the answer is:
apostrophe
'it may be misplaced by shopkeeper?' is the definition.
The definition suggests a singular noun which matches the answer.
'perhaps too haphazardly' is the wordplay.
'haphazardly' indicates anagramming the letters.
'perhaps'+'too'='perhapstoo'
'perhapstoo' is an anagram of 'APOSTROPHE'.
Can you help me to learn more?
(Other definitions for apostrophe that I've seen before include "in Charley's Aunt ?" , "At which point discarded letters" , "Single quote mark" , "Mark in exam's" , "address?" .)