Many crackers -- I pull them, but not hard (8)
I believe the answer is:
multiple
'many' is the definition.
(similar in meaning)
'crackers i pull them but not hard' is the wordplay.
'crackers' indicates anagramming the letters (informal term for mad).
'but not' suggests deleting specific letters.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'i'+'pull'+'them'='ipullthem'
'ipullthem' with 'h' taken out is 'ipulltem'.
'ipulltem' is an anagram of 'MULTIPLE'.
(Other definitions for multiple that I've seen before include "Having many parts or components" , "Having or involving many parts" , "Having several parts" , "Lit plume (anag)" , "Numerous and often varied" .)