To prevent something unpleasant from happening.

(idiomatic) To make a guess; to guess.

(marketing, business) An individual hired by a company to pose as a customer in order to evaluate the quality of its service. / (television) A guest star whose identity is kept secret.

(rare) A mudguard which is attached at the back of a bicycle saddle.

To be careful and alert to the possibility of danger.

To become less guarded; to allow oneself to become more vulnerable.

To guard; to maintain a stance of vigilance in order to protect.

plural of guard of honor

A joint-stock company on the insurance principle, serving as security for the integrity of cashiers, etc.

plural of guarantee association