Lying on the back, or with the face upward; -- opposed to prone.
source: Webster 1913
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.
source: Webster 1913
adjective satellite
lying face upward
source: WordNet 3.0
offering no resistance
Resistless hostages. No other colony showed such supine, selfish helplessness in allowing her own border citizens to be mercilessly harried.