FIDUCIARY Meaning of FIDUCIARY in English I . n. Trustee, depositary. II . a. 1.Confident, undoubting, trustful, firm, steadfast, unwavering, fiducial.2.Trusty, trustworthy, reliable.3.Held in trust, in the nature of a trust. Soule. Dictionary of English synonyms. Словарь английских синонимов. 2012