- a person or agency that undertakes certain responsibilities in connection with some other person or some group or activity, as in being a proponent, endorser, advisor, underwriter, surety, etc.
- a godfather or godmother; person who answers for a child, as at baptism, making the profession of faith and the promises prescribed
- in some Christian denominations, a person who acts as patron for someone being confirmed
- a business firm or other agency that alone or with others pays the costs of a radio or television program on which it advertises or promotes something
Origin of sponsorL, surety from spondere, to promise solemnly from Indo-European base an unverified form spend-, to bring a libation, vow from source Classical Greek spendein, to promise, spond?, libation