noun
water sprinkler truck; street washer
A vehicle equipped with a water tank and spray nozzles, used for watering plants, dust control, or cleaning streets.
夏の暑い日、散水車が道路に水をまいていた。
On a hot summer day, a water sprinkler truck was spraying water on the road.
Compound of 散水 (sansui, 'sprinkling water') + 車 (sha, 'vehicle').