Other forms: endorsed, endorsing, endorses
To endorse is to declare your support for a person or product publicly. Endorse a candidate, celebrity endorsement, fully endorse.
A newspaper endorses a candidate, a sportsperson endorses a brand, and endorsement deals are often worth more than the sport. The original sense is to sign the back of a document: endorse a cheque. In Britain, points for a driving offence are endorsed on a licence, so an endorsement there is a penalty rather than a compliment. Note endorsement, endorsee; and that endorse means to back, literally.
1verbendorseTo declare your support for a person or product publicly.
“The newspaper endorsed the opposition candidate a week before the election.”
2verbsignTo sign the back of a document.
“Please endorse the cheque on the back before you pay it in.”
endorse is an act of backing.
Also accepted in games: back
Old French endosser meant to put on the back, from Latin dorsum, back — the same root as dorsal. Signing the back of a document is the literal sense, and public support is the metaphor.
Latin
dossum
Old French
endosser — to put on the back
Middle English
endosse
Medieval Latin
indorso
English, today
endorse
Built from
Alteration influenced by Medieval Latin indorso of Middle English endosse, from Old French endosser (“to put on the back”), from Latin dossum, alternative form of dorsum (“back”), from which also dorsal (“of the back”). That is, the ‘r’ was dropped in dossum, which developed into Old French and then endosse, and then the ‘r’ was re-introduced into English via the Medieval Latin indorsare, which had retained the ‘r’. Note that the alternative spelling indorse also uses the initial ‘i’ from Latin (in-, rather than en-), but this form is now rare.
Etymology from Wiktionary, CC BY-SA