2 entries under this word
n. [Lat. supinum (sc. verbum), from supinus, bent or thrown backward, probably because, although furnished with substantive case-endings, it throws itself back, as it were, on the verb; It., Sp., & Pg. supino, Pr. supi, Fr. supin.] (Gram.) A verbal noun; or (according to C. F. Becker), a case of the infinitive mood ending, in Latin, in um and u, that in um being sometimes called the former supine, and that in u the latter supine.
a. [Lat. supinus, from super, above, on the top; It., Sp., & Pg. supino.]
Sense 1. Lying on the back, or with the face upward; — opposed to prone.
Sense 2. Leaning backward, or inclining with exposure to the sun.
If the vine On rising ground be placed on hills supine. Dryden.
Sense 3. Negligent; heedless; indolent; thoughtless; inattentive.
He became pusillanimous and supine, and openly exposed to any temptation. Woodward.
Synonyms—Negligent; heedless; indolent; thoughtless; inattentive; listless; careless; drowsy.