knot -- (a tight cluster of people or things; "a small knot of women listened to his sermon"; "the bird had a knot of feathers forming a crest")
knot -- (any of various fastenings formed by looping and tying a rope (or cord) upon itself or to another rope or to another object)
knot -- (a hard cross-grained round piece of wood in a board where a branch emerged; "the saw buckled when it hit a knot")
knot, gnarl -- (something twisted and tight and swollen; "their muscles stood out in knots"; "the old man's fists were two great gnarls"; "his stomach was in knots")