DATUMS

Verb

datums

Third-person singular simple present indicative form of datum

Noun

datums

plural of datum

Usage notes

This plural is permissible only in the sense of "fixed reference points". For all other senses, the plural is data.

Source: Wiktionary

DATUM

Da"tum, n.; pl. Data. Etym: [L. See 2d Date.]

1. Something given or admitted; a fact or principle granted; that upon which an inference or an argument is based; -- used chiefly in the plural. Any writer, therefore, who . . . furnishes us with data sufficient to determine the time in which he wrote. Priestley.

2. pl. (Math.)

Definition: The quantities or relations which are assumed to be given in any problem. Datum line (Surv.), the horizontal or base line, from which the heights of points are reckoned or measured, as in the plan of a railway, etc.

Source: Webster’s Unabridged Dictionary 1913 Edition