adj negligent; heedless; indolent; listless.
2. supine ·adj lying on the back, or with the face upward;
opposed to prone.
3. supine ·adj leaning backward, or inclining with exposure to the sun; sloping; inclined.
4. supine ·noun a verbal noun; or (according to c.f.becker), a case of the infinitive mood ending in -um and -u, that in -um being sometimes called the former supine, and that in -u the latter supine.