Lying on the back, or with the face upward: opposed to prone.Leaning backward; inclined; sloping: said of localities.Negligent; listless; heedless; indolent; thoughtless; inattentive; careless.In botany, lying flat with the face upward, as sometimes a thallus or leaf.n. A part of the Latin verb, really a verbal noun, similar to the English verbals in -ing, with two cases.Supinely.