ingoing

Ingoing is an adjective and, less commonly, a noun, describing something that moves toward the interior of a region or toward a reference point. It is the counterpart of outgoing or outbound, and it is most often found in technical, scientific, or engineering contexts where direction of flow, signals, or movement must be specified.

In practical use, ingoing is applied to physical processes (ingoing flow or ingoing current), waves or radiation entering a region (ingoing boundary conditions), and data or traffic entering a system (ingoing traffic). In physics and mathematics, ingoing boundary conditions specify that wave or particle motion is directed into a domain rather than away from it. In engineering and networking, the term may appear to emphasize the direction of entry, though more common terms such as incoming or inbound are frequently used instead to describe data or traffic that enters a system.

Etymology and variants: ingoing derives from the preposition in- plus going, and is used predominantly in specialized discourse. Some sources also spell it as in-going, though the one-word form ingoing is now standard in most technical writing.

Related terms include ingress, which denotes the act of entering or the point of entry; outbound and outgoing for opposite directions; incoming and inbound as widely used synonyms. Ingo ing is generally reserved for contexts where precise inward direction is important to the description of a process or boundary behavior.