1. An abnormal tufted growth of small branches on a tree or shrub caused by fungi or insects or other physiological disturbance
   - witches' broom, witch broom, hexenbesen

Type of: tuft, tussock

• onomastics
• onomatomania
• onomatopoeia
• onomatopoeic
• onomatopoeical
• onomatopoetic
• Onondaga
• Ononis
• Ononis repens
• Ononis spinosa
• Onopordon
• Onopordon acanthium
• Onopordum
• Onopordum acanthium
• Onosmodium
• onrush
• Onsager
• onset
• onshore
• onside
• onslaught
• onstage
• Ontarian
• Ontario
• ontic