(from Latin serica, “silk”), fabric much-used for military uniforms, made in an even-sided twill weave and usually clear-finished—that is, the fibre ends on the surface of the cloth are sheared or singed so that the twill weave is prominent. The resulting flat diagonal rib pattern goes from the lower left to the upper right selvage on the right side.

Serge was originally made of silk or wool but is now sometimes made of other single fibres or of wool blended with other fibres.