A person or entity legally or officially entrusted with the care, management, or safekeeping of property, assets, or records.
He is the custodian designated in the will.
The responsibility as a trustee of the trust property is heavy.
受託者 is a 'trustee' in the context of a trust agreement, emphasizing the fiduciary duty. 保管人 can be a trustee but also a custodian without full fiduciary powers.
Compound of 保管 (ほかん, 'custody, safekeeping') and 人 (にん, 'person'). The exact historical derivation is uncertain, but the word follows a common pattern for forming agent nouns.