cosponsor

noun

co·​spon·​sor (ˌ)kō-ˈspän(t)-sər 

variants or co-sponsor

plural cosponsors or co-sponsors

: a joint sponsor

The senator was a cosponsor for both bills.

Michigan Tech Student Relay For Life is a participating cosponsor of this event.

—The Daily Mining Gazette

cosponsor transitive verb

or co-sponsor

cosponsored or co-sponsored; cosponsoring or co-sponsoring

This year Simpson is carrying on the legislative struggle without Mazzoli, who has declined to cosponsor the bill without support from the Democratic House leadership …

—George Russell

The following summer, Bingham returned to Machu Picchu with an expedition co-sponsored by the National Geographic Society.

—Duane Damon

cosponsorship

(ˌ)kō-ˈspän(t)-sər-ˌship 

noun

or co-sponsorship

Increasingly, large urban malls are being built with the co-sponsorship of city governments.

—Witold Rybczynski

Examples of cosponsor in a Sentence

Recent Examples on the Web

The committee’s chairwoman, Assemblymember Buffy Wicks, D-Oakland, was a cosponsor on the bill, called the Housing Opportunities Made Equal Act. —Kate Wolffe, Sacbee.com, 23 Jan. 2026

But as of Wednesday, the legislation has no cosponsor in the Senate, making its path to becoming law more difficult. —Lawrence Mower, Miami Herald, 21 Jan. 2026

Khanna has 13 cosponsors on the bill so far, all Democrats. —Garrett Downs, CNBC, 18 Jan. 2026

The bill has 28 cosponsors, according to the Senate Majority Caucus. —Lucas Aulbach, Louisville Courier Journal, 13 Jan. 2026

Word History

First Known Use

1849, in the meaning defined above

Rhymes for cosponsor

• sponsor