glissette

from The Century Dictionary.

• noun A curve described by a point upon a rigid piece two other points of which slide upon two curves or upon the same curve.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Math.) The locus described by any point attached to a curve that slips continuously on another fixed curve, the movable curve having no rotation at any instant.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mathematics The locus described by any point attached to a curve that moves continuously along another fixed curve, the movable curve having no rotation at any instant.