Trusty
Trusty , adjective
1.
Admitting of being safely trusted; justly deserving confidence; fit to be confided in; trustworthy; reliable.
Your trusty and most valiant servitor.
2.
Hence, not liable to fail; strong; firm.
His trusty sword he called to his aid.
3.
Involving trust; as, a trusty business. [Rare] — Shakespeare