N-COUNT （驾驶员在交通高峰时段为避开主路车流而穿行的）小胡同，狭窄夹道 A rat run is a small street which drivers use during busy times in order to avoid heavy traffic on the main roads. （驾驶员在交通高峰时段为避开主路车流而穿行的）小胡同，狭窄夹道 [British, informal]