Share not quite worked out (8)
I believe the answer is:
quotient
'share' is the definition.
(thesaurus)
'not quite worked out' is the wordplay.
'worked out' indicates an anagram.
'not'+'quite'='notquite'
'notquite' is an anagram of 'QUOTIENT'.
(Other definitions for quotient that I've seen before include "rating?" , "The Q in IQ" , "Ratio of two quantities to be divided" , "Result of division sum" , "Three, when seven divided by two" .)