1. Heartily friendly and congenial
   - comradely, hail-fellow-well-met

See also: friendly

• ontogenesis
• ontogenetic
• ontogeny
• ontological
• ontologically
• ontologist
• ontology
• onus
• onward
• onward motion
• onwards
• onya
• onycha
• Onychium
• Onychogalea
• onycholysis
• Onychomys
• Onychophora
• onychophoran
• onychosis
• onymous
• onyx
• onyx marble
• onyxis
• oocyte