To border, or border on; to be physically close or conceptually akin to.
Showing bad taste.
Nearly; not clearly on one side or the other of a border or boundary, ambiguous.
Exhibiting borderline personality disorder.
Nearly; not entirely but nevertheless to a great extent.
A boundary or accepted division; a border.
An individual who has borderline personality disorder.
To touch bottom lightly and without damage, as a vessel in motion.
To perform a touch-and-go landing.
Precarious, delicate, risky, sensitive; of uncertain outcome (by analogy with a ship in shallow water).