1. Marked by unjust severity or arbitrary behaviour
   "tyrannous disregard of human rights"
   - oppressive, tyrannical

See also: domineering, tyrant

• onward
• onward motion
• onwards
• onya
• onycha
• Onychium
• Onychogalea
• onycholysis
• Onychomys
• Onychophora
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• onyx marble
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• Oom Paul Kruger
• oomph