Medical condition affected hearing mostly (6)
I believe the answer is:
hernia
'medical condition' is the definition.
'hernia' can be an answer for 'condition' (hernia is a kind of condition). I'm not sure about the 'medical' bit.
'affected hearing mostly' is the wordplay.
'affected' is an anagram indicator.
'mostly' means to remove the last letter.
'hearing' with its final letter taken off is 'hearin'.
'hearin' is an anagram of 'HERNIA'.
Can you help me to learn more?
(Other definitions for hernia that I've seen before include "Rupture, protrusion of organ through abdominal wall" , "Protrusion of organ through wall of body" , "Rupture in muscle tissue through which a structure protrudes" , "Protrusion of organ through wall of abdomen, a rupture" , "A rupture within the body" .)