1. Very angry
   - hot under the collar, spare [Brit]

See also: angry

• ostracod
• Ostracoda
• ostracoderm
• Ostracodermi
• Ostrava
• Ostrea
• Ostrea gigas
• Ostreidae
• ostrich
• ostrich fern
• Ostrogoth
• Ostrya
• Ostrya carpinifolia
• Ostrya virginiana
• Ostryopsis
• Ostwald
• Ostwald's theory of indicators
• Ostyak
• Ostyak-Samoyed
• Oswald
• Oswald Spengler
• Oswald Veblen
• oswego tea
• Otaheite arrowroot
• Otaheite arrowroot starch