1. Of an electrical system that uses or generates two or more alternating voltages of the same frequency but differing in phase angle
   - polyphase

See also: phase

• Old Bailey
• old bean
• old boy
• old boy network
• Old Bulgarian
• Old Bullion
• Old Catholic
• Old Catholic Church
• Old Church Slavic
• Old Church Slavonic
• old codger
• Old Colony
• old country
• Old Delhi
• Old Dominion
• Old Dominion State
• Old English
• Old English sheepdog
• Old Faithful
• old fart
• old fashioned
• Old French
• Old Frisian
• old geezer
• Old Glory