inverse number

Noun

 * 1)  Describes a morphophonological relationship between two grammatical number categories X and Y and two declension classes A and B such that the X form in A is to the Y form in A as the Y form in B is to the X form in B.
 * ''One example of inverse number in the proto-language is how the first declension featured a singular suffix -i and a plural suffix -u, meanwhile the second declension had a singular suffix -u and a plural suffix -i.
 * Nowadays, only the nothern dialect retains inverse number.