co-sponsornoun [ C ]
also cosponsor ukusUSa member of the US Congress who formally suggests a new law with another member:
The Historic Home and Neighborhood Preservation Act was introduced by Rep. Tom Tangretti about two years ago, with Rep. Mike Sturla as a co-sponsor.
co-sponsor
verb [ T ] also cosponsor
The highways bill was cosponsored by 38 Republicans and 24 Democrats.