lanc·er 
(lănsər)
(lănsər)n.
1. A cavalryman armed with a lance.
2. A member of a regiment originally armed with lances.
3. lancers (used with a sing. verb)
a. A kind of quadrille.
b. The music for this dance.
[French lancier, from Old French, maker of lances, from lance, lance; see LANCE.]