Condition in maths reworked attracting top grade (6)
I believe the answer is:
asthma
'condition' is the definition.
(asthma is a kind of condition)
'maths reworked attracting top grade' is the wordplay.
'reworked' indicates an anagram.
'attracting' indicates putting letters inside (inserted letters are attracted inside).
'top grade' becomes 'a' (top academic grade).
'maths' is an anagram of 'sthma'.
'sthma' going around 'a' is 'ASTHMA'.
'in' acts as a link.
(Other definitions for asthma that I've seen before include "breathing problems" , "Chest disorder" , "Shortage of breath" , "Distressing ailment affecting breathing" , "Lung condition" .)