What does "device" mean?

Additional senses

1. 2.2. Power of devising; invention; contrivance. I must have instruments of my own device. Landor.
2. 3.(a) An emblematic design, generally consisting of one or more figures with a motto, used apart from heraldic bearings to denote the historical situation, the ambition, or the desire of the person adopting it. See Cognizance. (b) Improperly, an heraldic bearing. Knights-errant used to distinguish themselves by devices on their shields. Addison. A banner with this strange device -Excelsior. Longfellow.
3. 4.Anything fancifully conceived. Shak.
4. 5.A spectacle or show. [Obs.] Beau. & Fl.
5. 6.Opinion; decision. [Obs.] Rom. of R. -- Device, Contrivance. Device implies more of inventive power, and contrivance more of skill and dexterity in execution. A device usually has reference to something worked out for exhibition or show; a contrivance usually respects the arrangement or disposition of things with reference to securing some end. Devices were worn by knights-errant on their shields; contrivances are generally used to promote the practical convenience of life. The word device is often used in a bad sense; as, a crafty device; contrivance is almost always used in a good sense; as, a useful contrivance.