(rail transport) The outline of the space occupied by a rail vehicle when in motion, including the effects of tilt, sway, track cant, etc.

plural of nuclear envelope

One whose job is to manually insert sheets of printed paper into envelopes for mailing, especially as an example of a person whose work is menial and unfulfilling.

plural of padded envelope

A large thick envelope, now usually coated with foam or bubblewrap, used to protect fragile items in the mail.

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

plural of Dahlke envelope

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

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

plural of blind envelope