Definition of: endorse

(in·dôrs′) v.t. ·dorsed, ·dors·ing
1. To write upon the back of; especially, to write one's name on the back of (a check, draft, etc.) to assign it or to guarantee its payment; to write one's name on the back of (a check, etc.) in exchanging the document for the cash it represents.
2. To indicate receipt of (a sum) by signing one's name.
3. To give sanction to. See synonyms under ACKNOWLEDGE, AFFIRM, CONFESS, JUSTIFY, RATIFY. Also spelled indorse. [<OF endosser <Med. L indorsare <L in- on + dorsum back; partially refashioned after L]
—en·dors′a·ble adjective
—en·dors′er, en·dor′sor noun