Properly, a knot; a knob; hence,

In surgery, a swelling of the periosteum, tendons or bones.

In astronomy, the point where the orbit of a planet intersects the ecliptic. These points are two, and that where a planet ascends northward above the plane of the ecliptic, is called the ascending node, or dragons head; that where a planet descends to the south, is called the descending node, or dragons tail.

In poetry, the knot, intrigue or plot of a piece, or the principal difficulty: .

In dialing, a point or hole in the gnomon of a dial, by the shadow or light of which, either the hour of the day in dials without furniture, or the parallels of the suns declination and his place in the eclipticin dials with furniture, are shown.