Here's a why why why for you David...
Why, at the airport, do they call it the TERMINAL?
L
Ha ha ha! I see your point. But it is being used as a noun, not an adjective.
Here is the Definition:ter·mi·nal (tûrm-nl) ADJECTIVE: Of, at, relating to, or forming a limit, boundary, extremity, or end.
Botany Growing or appearing at the end of a stem, branch, stalk, or similar part.
Of, at, relating to, or being the end of a section or series; final. See Synonyms at last 1.
Relating to or occurring in a term or each term: terminal inventories.
Causing, ending in, or approaching death; fatal: terminal cancer; a terminal patient.
NOUN: A point or part that forms the end.
An ornamental figure or object placed at the end of a larger structure; a finial.
Electricity
A position in a circuit or device at which a connection is normally established or broken.
A passive conductor at such a position used to facilitate the connection.
Either end of a railroad or other transportation line; a terminus.
A station at the end of a transportation line or at a major junction on a transportation line.
A town at the end of a transportation line.
Computer Science A device, often equipped with a keyboard and a video display, through which data or information can be entered or displayed.
It is interesting to wonder how the word became associated with transportation. Perhaps it goes back to ancient times. Did the greeks us the word Terminus to imply a port or destination?
To say:"Your flight terminates in Boston at the Terminal." Adjective and noun.