Brand X

[ eks ]
/ ɛks /

noun

(in advertising) a competing brand or product not referred to by name but implied to be of inferior quality.
an unknown or little-known brand name or a product bearing it.
any item that one chooses not to refer to by name, especially when used as a basis of comparison.

Origin of Brand X

First recorded in 1965–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019