IPA: /ˌdɪsəˈlaʊəns/
KK: /dɪsəˈlaʊəns/
The act of refusing to allow something or taking away permission.
The disallowance of the proposal surprised many members of the committee.
Disallowance → It is formed from "dis-" (meaning apart or not) and "allow" (from Old French *alouer*, meaning to permit or grant). The suffix "-ance" (meaning the state or condition of) indicates the act or state of not allowing. Thus, disallowance refers to the state of not permitting something.
Think of 'not' ('dis-') allowing something ('allow') — that's why disallowance means the state of not permitting.