cusp of the first kind
cusp of the first kind[′kəsp əvthə ′fərst ‚kīnd]
A cusp such that the two portions of the curve adjacent to the cusp lie on opposite sides of the limiting tangent to the curve at the cusp. Also known as simple cusp.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.