Terminal (adjective)

1. Of or relating to a terminal or to the end.
2. Situated at or forming the end or extremity of something.
3. Relating to or being a terminal illness, a disease from which recovery is impossible.

Origin:

Late middle english: from latin terminalis, from terminus "end, boundary". the noun (late 19th century) originally referred to a place where a railway line ended, later also to a place where air or bus passengers disembarked.

Examples:

1. The terminal building at the airport is undergoing renovations.
2. The terminal stage of a terminal illness.
3. The terminal point of a line segment.
4. A terminal case of depression.
5. A terminal diagnosis is a devastating blow to anyone.