Knot

Brightly colored rope forming a knot. Knot type varies across platform, with most designs showing a square knot, a figure eight knot, or a carrick bend. Samsung's design appears to be a carrick bend, but upon closer inspection, it is not correctly tied and would fall apart with a gentle tug. 

Used to talk about rope or knots in general. Sometimes used in the context of marriage alongside the idiom tying the knot. Also used in the kink community to talk about bondage. May be used as a stand-in for the word 'not' in emoji rebus puzzles.