Commensurable.

Chambers's Encyclopaedia, Volume 3: Catarrh to Dion, p. 381

Commensurable. Two quantities or numbers are said to be commensurable which are of the same kind, and each of which contains a third quantity or number a certain number of times without remainder; or when both can be measured exactly by the same unit, however small.

Source scan(s): p. 0392