Astronomy Answers
From the Astronomical Dictionary

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The description of the word you requested from the astronomical dictionary is given below.

the node

The nodes of the orbit of a celestial body are the two places where the orbit passes through the base plane of the coordinate system. The node at which the object goes through the base plane from south to north is called the ascending node, and the node at which the object goes from north to south through the base plane is called the descending node.