IPA: /koʊˈspɒnsər/
KK: /koʊˈspɒnsər/
To jointly support or sponsor an event, project, or initiative with another party.
The two organizations decided to cosponsor the community festival this year.
Past: cosponsored
Past Participle: cosponsored
Cosponsor → It is formed from "co-" (meaning together) and "sponsor" (from Latin "sponsorem", meaning a guarantor or one who pledges). The word "cosponsor" means to jointly sponsor or support something together with another party.
Think of 'together' ('co-') when you picture two parties 'pledging' ('sponsor') support for an event or initiative.