car-pool

noun Also car pool.

1. Also car·pool·ing, car pooling. an arrangement among a group of automobile owners by which each owner in turn drives the others or their children to and from a designated place.
2. those included in such an arrangement.

verb (used without object)

3. Also car-pool. to form or participate in a carpool.

verb, noun

1. another term for carshare

n.

also carpool, 1942, American English, from car + pool (n.2). As a verb from 1962. Related: Carpooled; carpooling.