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 legislation is being sponsored by Rep. Nydia M. Velázquez, who introduced it on June 12, 2025, with a number of other House Democrats signed on as cosponsors. —Billal Rahman dan Gooding, MSNBC Newsweek, 1 July 2025

The bottom line: The bill currently has three Democratic cosponsors, but the issue seemed to be eroding chances for strong bipartisan support. —Brady Dale, Axios, 2 Apr. 2025

Five Republicans have signed onto the impeachment articles as cosponsors. —Kaia Hubbard, CBS News, 20 Mar. 2025

Since it was introduced by Grassley and Cantwell on Thursday, four other Republicans have signed as cosponsors, including Senators Mitch McConnell, Thom Tillis, Lisa Murkowski and Jerry Moran. —Newsweek Staff, MSNBC Newsweek, 5 Apr. 2025

Word History

First Known Use

1849, in the meaning defined above

Rhymes for cosponsor

• sponsor