1. To give surety or assume responsibility; SYN. vouch.
2. To make certain of; SYN. ensure, insure, assure, secure.
3. To stand behind; SYN. warrant.

1. To make secure; to give assurance against harm; to guarantee safety to.
2. To give assurances or proof; to justify; to maintain; to sanction.
3. To give a guarantee or warranty to; to assure as if by giving a warrant to.
4. To secure to, as a grantee, an estate granted; to assure.