Theatre Terminology
Pronounced "sike"
Short for cyclorama. There are several kinds:

fly cyc: a u-shaped expanse of light blue or white canvas enclosing the acting area on three sides. It’s raised and lowered by a counter weight system. Used for sky effects.
trip cyc: similar to a fly cyc, but will fold as it is raised requiring less grid height.
linnebach cyc: This one is suspended from a curved track and moves horizontally to store in the wings. It’s named after Adolph Linnebach.