A totally and completely useless individual whose sole purpose in life is to stand there and look good. They have the potential to do something useful, but just won't. Chromos generally go to great lengths to avoid responsibility. They are usually very self-centered, incredibly dense, impulsive liars, and are almost always undeniably hot.

Believe it or not, this term comes from the word "chromoplast," an organelle within a plant cell that is created once a chloroplast dies. Chromoplasts, like chromos, are useless. They only provide nice colors for the plant, hence the general hotness of chromos.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.

Any useless, annoying individual. The word implies low intelligence and social status, and/or lack of moral values.
Only moderately insulting, the term conveys the idea that the person thus designated is looked-down on, but not hated. Comes from chromosome, hinting that the insultee might be missing a few.

"Window licker", "spakka", "spastic"

A substandard human being missing a chromasone, like a downs syndrome.