1. Not exhibiting the qualities expected in a friendly neighbour
   - unneighborly [US]

See also: unfriendly

• Onsager
• onset
• onshore
• onside
• onslaught
• onstage
• Ontarian
• Ontario
• ontic
• onto
• ontogenesis
• ontogenetic
• ontogeny
• ontological
• ontologically
• ontologist
• ontology
• onus
• onward
• onward motion
• onwards
• onya
• onycha
• Onychium
• Onychogalea