A chit, perhaps, or letter (5)
I believe the answer is:
aitch
'letter' is the definition.
(aitch is the name for the letter H)
'a chit perhaps' is the wordplay.
'perhaps' indicates an anagram.
'chit' anagrammed gives 'itch'.
'a'+'itch'='AITCH'
'or' is the link.
(Other definitions for aitch that I've seen before include "8th letter of the alphabet" , "bone" , "first bit of hymn?" , "that may be dropped" , "that I will immediately succeed" .)