postmark n 1: a cancellation mark stamped on mail by postal officials; indicates the post office and date of mailing v 1: stamp with a postmark to indicate date and time of mailing [syn: {postmark}, {frank}]
Postmark \Post"mark`\, n. The mark, or stamp, of a post office on a letter, giving the place and date of mailing or of arrival. [1913 Webster]
Postmark \Post"mark`\, v. t. [imp. & p. p. {Postmarked}; p. pr. & vb. n. {Postmarking}.] To mark with a post-office stamp; as, to postmark a letter or parcel. [1913 Webster]