swear by

Also found in: Dictionary, Thesaurus, Idioms.
See: trust
References in periodicals archive ?
On the one hand, his book fulfils by elaboration his pithy summary: 'people used mainly to swear by or to but now swear mostly at': asseveration and invocation giving way to profanity and ejaculation as society moves, in his Viconian image, from the sacred to the secular phase.