[noun] [C] [formal]A guarantor is a person who makes certain that something happens or that something is protected.The armed forces see themselves as the guarantors of free elections in the country.(legal) A guarantor is a person who formally accepts responsibility for you or for something that belongs to you.You must have a guarantor in order to get a visa to enter the country.
GUARANTOR
Meaning of GUARANTOR in English
Cambridge English vocab. Кембриджский английский словарь. 2012