safeguard Definition

1. A person, device or arrangement giving protection against danger or harm.

Thesaurus: defence, guard, shield, surety, escort, precaution, preventive.
2. A safe-conduct.

1. To protect from harm; to ensure the safety of someone or something.

Thesaurus: defend, guard, insure, assure, preserve, protect, screen, shield, secure, shelter; Antonym: endanger, jeopardize.