Lan″cet (?), n. [F. lancette, dim. of lance lance. See Lance.] 1. A surgical instrument of various forms, commonly sharp-pointed and two-edged, used in venesection, and in opening abscesses, etc.
2. (Metal.) An iron bar used for tapping a melting furnace. Knight.
Lancet arch(Arch.), a pointed arch, of which the width, or span, is narrow compared with the height. — Lancet architecture, a name given to a style of architecture, in which lancet arches are common; — peculiar to England and 13th century. — Lancet fish. (Zoöl.) (a) A large, voracious, deep-sea fish (Alepidosaurus ferox), having long, sharp, lancetlike teeth. (b) The doctor, or surgeon fish.