Historical role in the Edo period: a high-ranking servant in a samurai household responsible for general management and accounting, ranking just below the chief retainers. Often encountered in period dramas and historical texts.
See also: 御用人
useful person; handy person
Modern, somewhat colloquial extension of the historical term. Refers to someone who is generally capable and can be relied upon for various tasks, like a jack-of-all-trades. Often used in a light, appreciative tone.
In period dramas, scenes often show the steward examining the account books.
His ancestor served as a steward for the domain during the Edo period.
He can do anything, so he's a really useful person.
Every company could use a jack-of-all-trades.
Compound of 用 (よう, 'business, use') and 人 (にん, 'person'). The historical sense of a steward in a samurai household dates back to the Edo period. The modern casual sense of 'useful person' is a natural semantic extension.