A driving or running towards; approach; impulse; also, the act of striking against.

The near approach of one heavenly body to another, or to the meridian; a coming into conjunction; as, the appulse of the moon to a star, or of a star to the meridian.

(N) - striving approach to engagement

The apparent close approach of one celestial body to another. This is a line of sight effect.

Appulse is an astronomical term that refers to the very near approach of one celestial object to another, as seen from a third body. Usually it refers to the close approach of two planets together in the sky, or of the Moon to a star or planet as the Moon follows its monthly orbit around Earth, as seen by an observer located on Earth. An "appulse" can also be referred to as a conjunction.