The Collaborative International Dictionary of English v.0.48:
Slumbrous \Slum"brous\, a. Slumberous. --Keats. [1913 Webster]WordNet (r) 3.0 (2006):
slumbrous adj 1: quiet and tranquil; "a slumberous June morning" [syn: slumberous, slumbrous] 2: inclined to or marked by drowsiness; "slumberous (or slumbrous) eyes"; "`slumbery' is archaic"; "the sound had a somnolent effect" [syn: slumberous, slumbery, slumbrous, somnolent]