substituted service
See service.

• opinio juris
• opinion
• opinion evidence
• OPSI
• option
• optional clause
• option to purchase
• oral agreement
• oral evidence
• orality
• order
• order of committal
• order of discharge
• orders for accounts and inquiries
• Orders in Council
• Orders of Council
• ordinance
• ordinary legislative procedure
• ordinary resolution
• ordinary share
• organ donation
• original evidence
• originating summons
• origin system
• ouster