Suitability of female, one giving evidence after wife dismissed (7)
I believe the answer is:
fitness
'suitability' is the definition.
(fitness is a kind of suitability)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for fitness that I've seen before include "condition" , "Suitability - health" , "State of good health" , "Well-being" , "Competence" .)