1. Coming next after the twenty-ninth in position
   - thirtieth

See also: ordinal

• oarlock
• oarsman
• oarsmanship
• oarswoman
• OAS
• oasis
• oast
• oast house
• oat
• oat cell carcinoma
• oat grass
• oatcake
• oaten
• Oates
• oath
• oatmeal
• oatmeal cookie
• Oaxaca
• Oaxaca de Juarez
• Ob
• Ob River
• ob-gyn
• Obadiah
• Obama
• obbligato