Know why cattywampus was trending last week?
1973, initialism from liquid crystal display, which is attested from 1968.
Short for liquid-crystal display. A low-power, flat-panel display used in many digital devices to display numbers or images. It is made of a liquid containing crystals that are affected by electric current, sandwiched between filtering layers of glass or plastic. LCDs do not produce light of their own; instead, when electric current is passed through the material, the molecules of the "liquid crystal" twist so that they either reflect or transmit light from an external source.