knot
noun
°A looping of a piece of string or of any other long, flexible material that cannot be untangled without passing one or both ends of the material through its loops.
"Climbers must make sure that all knots are both secure and of types that will not weaken the rope."
°(of hair etc) A tangled clump.
"The nurse was brushing knots from the protesting child's hair."
verb
°To form into a knot; tie with (a) knot(s).
°To form wrinkles in the forehead, as a sign of concentration, concern, surprise, etc.
synonyms: bind, tie, knit