The word keying has a number of meanings:

• Junk Keying - Chinese type of ship
• keying (cryptography) is the installation of key material into a device.
• keying (telecommunications) is a form of modulation where the modulating signal takes one of two or more values at all times. For example: "on" or "off", "mark" or "space". The name derives from the Morse code key used for telegraph signalling.
• keying (graphics) is an informal term for compositing two full frame images together, by discriminating the visual information into values of color and light.
• keying (vandalism) is using a key to scratch the paint on car as a form of vandalism.