As a Noun: 1. A place in a piece of string, rope, or cloth where one end has been passed through a loop and pulled tight. You do this in order to join two things together or to keep something firmly in place. English = knot. As a Verb or Adjective: 1. To tie a knot in a piece of string, rope, or cloth; to fasten something using a knot. 2. To fasten one thing to another, often using string or rope. English = tie, tie up.