Apotome

Apotomē (Greek: ἀποτοµή) is an archaic mathematical term which, according to Webster's 1828 Dictionary, is the difference of two quantities that are commensurable only in power. According to Bailey's 1761 Dictionary it is "an irrational remainder or residual when from a rational line a part is cut off which is only commensurate in power to the whole line". It appears not to be in modern usage.