rachis: Meaning and Definition of

ra•chis

1. the axis of an inflorescence when somewhat elongated, as in a raceme.
2. (in a pinnately compound leaf or frond) the prolongation of the petiole along which the leaflets are disposed.
3. any of various axial structures.
2. the part of the shaft of a feather bearing the web. See illus. under
3. See