trusty
adjective [ before noun ] mainly humorous uk/ˈtrʌs.ti/ us/ˈtrʌs.ti/
（尤指因为长期拥有或使用而）可信任的，可信赖的;可靠的
able to be trusted, especially because of having been owned and used for a long time
I did the entire three hundred miles on my own - just me and my trusty bike. 整个300英里的路程都是我独自骑过来的——就只有我和我那让人放心的自行车。
Compare: trustworthy