1. Involving four parties
   - four-party

See also: many-sided, multilateral

• Haplopappus
• Haplopappus acaulis
• Haplopappus phyllocephalus
• Haplopappus spinulosus
• Haplosporidia
• haplosporidian
• haplotype
• haply
• happen
• happen upon
• happening
• happenstance
• happily
• happiness
• happy
• happy chance
• happy event
• happy hour
• happy-clappy
• happy-go-lucky
• Hapsburg
• haptic
• haptic sensation
• haptically
• haptoglobin