stray 偏离的，迷失的

例句：Stray dogs are usually put to sleep if no one claims them.
走失的狗如无人认领通常就不让它再生存了.

astray 走偏地，误入歧途地，迷路地

例句：An error, the breadth of a single hair, can lead you a thousand li astray.
差之毫厘, 谬以千里。