1. In a stupid manner
   - densely, obtusely 
2. In an inarticulate manner
   "I nodded dumbly and he slit the envelope"

See also: dumb

• monopoly
• monopoly board
• monopsony
• monopteral
• monorail
• monorchidism
• monorchism
• monosaccharide
• monosaccharose
• monosemous
• monosemy
• monosexual
• monosodium glutamate
• monosomy
• monospaced font
• monostotic fibrous dysplasia
• monosyllabic
• monosyllabic word
• monosyllabically
• monosyllable
• monotheism
• monotheist
• monotheistic
• Monothelitism
• monotone