Straggler

Part of speech: noun (n.)

1. One who straggles, or departs from the direct or proper course, or from the company to which he belongs; one who falls behind the rest; one who rambles without any settled direction.

2. A roving vagabond. Shak.

3. Something that shoots, or spreads out, beyond the rest, or too far; an exuberant growth. Let thy hand supply the pruning knife, And crop luxuriant stragglers. Dryden.

4. Something that stands alone or by itself.