POSTMARKS

Noun

postmarks

plural of postmark

Verb

postmarks

Third-person singular simple present indicative form of postmark

Source: Wiktionary

POSTMARK

Post"mark`, n.

Definition: The mark, or stamp, of a post office on a letter, giving the place and date of mailing or of arrival.

Post"mark`, v. t. [imp. & p. p. Postmarked; p. pr. & vb. n. Postmarking.]

Definition: To mark with a post-office stamp; as, to postmark a letter or parcel.

Source: Webster’s Unabridged Dictionary 1913 Edition