service road (AmE also frontage road) noun [C]

a small road that runs parallel to a main road, that you use to reach houses, shops/stores, etc.

• operating loss
• operating margin
• operating profit
• operating strategy
• operating system
• operation
• operational
• operation process chart
• operations management
• operations manual
• operations research
• operative
• operator
• opinion leader
• OPM
• opportunism
• opportunist
• opportunity
• opportunity cost
• opportunity to see
• oppose
• opposite number
• optical character recognition
• optimal
• optimism