/ruyd"shair'ing/ , adj.
1. Also, rideshare . of or pertaining to sharing rides or transportation, esp. among commuters: The agency was set up to devise a ridesharing program.
n.
2. an act or instance of sharing rides or transportation, esp. by commuters: A statewide campaign to encourage ridesharing would reduce overcrowding on the highways.
[ RIDE + SHARE 1 + -ING 1 ]