Inbound means coming in towards a place. An inbound flight is arriving, an inbound train is heading into the city, and an inbound call is one somebody else made to you.
It is a logistics and traffic word, and it lives almost entirely as an adjective before a noun — inbound freight, the inbound lane, inbound traffic. You do not say the plane is inbound to describe it landing normally; you say it when you are tracking it, which is why the word feels like air traffic control and warehouses. Its opposite, outbound, behaves the same way. Marketing has borrowed inbound for the strategy of getting customers to come to you rather than chasing them, and there the contrast with outbound is the entire meaning.
1adjectiveinboundTravelling towards a place rather than away from it.
“All inbound trains were delayed by the storm.”
synonyms: incoming, arriving
2adjectivegoodsOf goods or calls, coming in to an organisation.
“The warehouse handles inbound deliveries in the morning.”
3adjectivemarketingIn marketing, based on drawing customers in rather than approaching them.
“Their whole inbound strategy is a blog and a newsletter.”
inbound is a direction of travel.
From in + bound.
Etymology from Wiktionary, CC BY-SA
Practised in Shipping & Logistics, Word Building