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. • A tangled clump of hair or similar. • A maze-like pattern. • A non-self-intersecting closed curve in (e.g., three-dimensional) space that is an abstraction of a knot (in sense 1 above). • A difficult situation. • The whorl left in lumber by the base of a branch growing out of the tree's trunk. • Local swelling in a tissue area, especially skin, often due to injury. • A tightened and contracted part of a muscle that feels like a hard lump under the skin. • A protuberant joint in a plant. • Any knob, lump, swelling, or protuberance. • The swelling of the bulbus glandis in members of the dog family, Canidae. • The point on which the action of a story depends; the gist of a matter. • A node (point at which the lines of a funicular machine meet from different angular directions) • A kind of epaulet; a shoulder knot. • A group of people or things. • A bond of union; a connection; a tie. • A unit of speed, equal to one nautical mile per hour. • A unit of indicated airspeed, calibrated airspeed, or equivalent airspeed, which varies in its relation to the unit of speed so as to compensate for the effects of different ambient atmospheric conditions on aircraft performance. • A nautical mile. • The bulbus glandis. • A group of snakes, intertwined.