straggler

Someone who goes against the direct or proper course, or from the company to which they belong.

She recounted her life in pre-World War II Eastern Europe and how a ragtag band of Red Army stragglers, escaped prisoners of war and Jewish and gentile Resistance fighters — including some women — harassed the Germans behind the Wehrmacht’s front lines in the forests and swamps of what is now Belarus.

One who falls behind the rest, for example in a race.

This isn't the 1970s, when the UK stood out as the European straggler.

One who roams without any settled direction.

A migratory animal found away from its usual range.

A roving vagabond.