Membranous \Mem"bra*nous\, a. [Cf. F. membraneux.]

1. Pertaining to, consisting of, or resembling, membrane; as, a membranous covering or lining.

2. (Bot.) Membranaceous.

Membranous croup (Med.), true croup. See Croup.

Source: Webster's Revised Unabridged Dictionary (1913)