Source : Webster's Revised Unabridged Dictionary (1913)

Straggler \Strag"gler\, 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.

Source : WordNet®

straggler
     n : someone who strays or falls behind [syn: {strayer}]