flanker

noun

1. a person or thing that flanks.
2. Military. one of a body of soldiers placed on the flank of an army to guard a line of march.
3. Fortification. a fortification projecting so as to defend another work or to command the flank of an assailing body.
4. Football.
   1. Also called flank·er·back.an offensive back who lines up outside of an end.
   2. split end.

noun

1. one of a detachment of soldiers detailed to guard the flanks, esp of a formation
2. a projecting fortification, used esp to protect or threaten a flank
3. rugby a wing forward