(US) An envelope whose mailing for an authorized purpose does not requiring postage, while its unauthorized use may be penalized.

An airmail envelope with a distinct pattern of spaced diamonds in alternating red and blue colours around the outer edge.

plural of Dahlke envelope

plural of blind envelope

(marketing) A plain envelope with no window showing the contents, used to make junk mail resemble legitimate correspondence.

simple past tense and past participle of stretch the envelope

present participle of stretch the envelope

Synonym of push the envelope

Third-person singular simple present indicative form of push the envelope

simple past tense and past participle of push the envelope