in ‧ ca ‧ pa ‧ ci ‧ ty /ˌɪnkəˈpæsəti, ˌɪnkəˈpæsɪti/ BrE AmE noun [singular, uncountable] formal
lack of the ability to do things or to do something:
temporary incapacity through illness
mental/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.