Lancer \Lan"cer\, n. [Cf. F. lancier.]

1. One who lances; one who carries a lance; especially, a member of a mounted body of men armed with lances, attached to the cavalry service of some nations. --Wilhelm.

2. A lancet. [Obs.]

3. pl. (Dancing) A set of quadrilles of a certain arrangement. [Written also lanciers.]

Source: Webster's Revised Unabridged Dictionary (1913)