Meaning

• Anything that assures a certain outcome.

  "Can you give me a guarantee that he will be fit for the match?"

• A legal assurance of something, e.g. a security for the fulfillment of an obligation.

• More specifically, a written declaration that a certain product will be fit for a purpose and work correctly; a warranty

  "The cooker comes with a five-year guarantee."

• The person to whom a guarantee is made.

• A person who gives such a guarantee; a guarantor.

Meaning

• To give an assurance that something will be done right.

• To assume or take responsibility for a debt or other obligation.

• To make something certain.

  "The long sunny days guarantee a good crop."