Definition of slumbrous in US English:

slumbrous

(also slumberous)

adjective

literary
  • See slumber

    • ‘But when he'd asked, when he'd lifted a hand to my face and looked at me with those slumberous green eyes of his, any logic I'd possessed had crumbled like nothing more than a flimsy, false idol.’
    • ‘Henry David Thoreau described the song of one species as ‘a slumberous breathing,’ an ‘intenser dream.’’
    • ‘A woman with a coy smile and slumberous eyes could gain access to locales and secrets a male counterpart would have to kill for.’
    • ‘The waking of the wood may mean that the slumbrous dream was not real anyway, that daytime reality has now supervened, replacing defiance with pleasant companionship.’
    • ‘Charlie had almost dozed off into a restless sleep when Richie's voice startled him out of his slumberous state.’

Pronunciation

slumbrous

/ˈsləmb(ə)rəs//ˈsləmb(ə)rəs/