Breach area in climbing in pursuit of that woman (6)
I believe the answer is:
hernia
'breach' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'area in climbing in pursuit of that woman' is the wordplay.
'area' becomes 'a' (maths abbreviation).
'climbing' says the letters should be written in reverse (in a down clue, letters climb up).
'in pursuit of' means one lot of letters go next to another (some letters chase after others).
'that woman' becomes 'her' (her refers to a woman).
'a'+'in'='ain'
'ain' backwards is 'nia'.
'nia' after 'her' is 'HERNIA'.
Can you help me to learn more?
(Other definitions for hernia that I've seen before include "Rupture in muscle tissue through which a structure protrudes" , "Protrusion of organ throung abdinen, rupture" , "A rupture within the body" , "Protrusion of organ through wall of body" , "Rupture, protrusion of organ through abdominal wall" .)