slumbrous

from 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}]

from The Collaborative International Dictionary of English v.0.48

Slumbrous \Slum"brous\, a.
   Slumberous. --Keats.
   [1913 Webster]