Evidence of his mental incapacity was never produced in court.incapacityin‧ca‧pa‧ci‧ty /ˌɪnkəˈpæsəti/ noun [singular, uncountable] formal 
temporary incapacity through illnessmental/physical/intellectual etc incapacity Evidence of his mental incapacity was never produced in court.incapacity to do something The main problem is the author’s incapacity to convey his ideas.
EXAMPLES FROM OTHER DICTIONARIES
- mental incapacity
- Even as he sensed his incapacity to make such a choice, it was made for him.
- It is in respect of property and contract that the incapacity of infancy has its most general operation.
- It would be a mistake to regard the condition of infancy as one of uniform incapacity throughout and for all purposes.
- The food crisis was not the result of any incapacity by the Soviet Union to grow enough food to feed its population.
- They were convinced of the incapacity of the free market significantly to diminish poverty and inequality.
- This incapacity is a one-sided one.
- This subsection makes provision for the death, bankruptcy or incapacity of a licence-holder during the currency of a licence.
- Was it not uneconomic to employ older workers whose apparent competence simply masked inevitably growing incapacity?
COLLOCATIONS FROM THE ENTRY Evidence of his mental incapacity was never produced in court.
lack of the ability to do things or to do something: Evidence of his mental incapacity was never produced in court. temporary incapacity through illnessmental/physical/intellectual etc incapacity Evidence of his mental incapacity was never produced in court.incapacity to do something The main problem is the author’s incapacity to convey his ideas.