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

See also: ordinal

• optic axis
• optic chiasm
• optic chiasma
• optic cup
• optic disc
• optic disk
• optic nerve
• optic radiation
• optic tract
• optical
• optical aberration
• optical activity
• optical art
• optical bench
• optical character recognition
• optical condenser
• optical crown
• optical crown glass
• optical density
• optical device
• optical disc
• optical disk
• optical fiber
• optical fibre
• optical flint