noun
number of words spoken; talkativeness
Used in set phrases like 口数が多い (talkative) and 口数が少ない (quiet, taciturn). Refers to how much a person speaks.
See also: 口数が多い
彼は口数が少ないが、仕事は確かだ。
He doesn't say much, but his work is solid.
When I'm nervous, I become talkative.
noun
number of dependents; number of mouths to feed
Refers to the number of people one must support financially, often used in contexts of household budgeting or social welfare.
口数が増えると生活費もかさむ。
When the number of dependents increases, living expenses also rise.
noun
number of items; number of shares; number of applications
Used for counting discrete things like shares, applications, or pieces. Less common than the first two senses; often replaced by 数 or 個数 in everyday speech.
応募の口数が予想を上回った。
The number of applications exceeded expectations.