off-ramp
Word family
Synonym discussion
Sense: noun/1
Exit ramp is the closest everyday synonym in North American English and often appears on road signs or in traffic reports. Off-ramp usually feels slightly more conversational and clearly contrasts with on-ramp. Slip road is the common British term, but it can mean either a road for entering or leaving a motorway, so you often need extra context. Turnoff is broader and can describe any place where a vehicle leaves one road for another, not only a highway exit. If you are talking about a numbered highway exit, off-ramp or exit ramp is the most exact choice. You take an off-ramp from the freeway, but you might make a turnoff from a smaller local road.
Etymology
Formed in American English from off and ramp for the road that carries traffic away from a major highway. The figurative sense developed later from the image of leaving the main route and stepping out of a difficult course of action.