1. Deliberately impassive in manner
   "his face remained expressionless as the verdict was read"
   - deadpan, impassive, poker-faced, unexpressive, straight-faced

See also: incommunicative, uncommunicative

• Onoclea struthiopteris
• onomancer
• onomancy
• onomastic
• onomasticon
• onomastics
• onomatomania
• onomatopoeia
• onomatopoeic
• onomatopoeical
• onomatopoetic
• Onondaga
• Ononis
• Ononis repens
• Ononis spinosa
• Onopordon
• Onopordon acanthium
• Onopordum
• Onopordum acanthium
• Onosmodium
• onrush
• Onsager
• onset
• onshore
• onside