- button (knob or small disc serving as a fastener)
- knot (i.e. a loop of string or any other long flexible material which cannot be untied without pulling part of the string through the loops)
- ik zit in de knoop — I'm in a hard spot: I'm all tied up.
- (mathematics) knot
- (nautical) knot (i.e. a unit of velocity, corresponding to traveling a distance of 1 nautical mile per hour)