a.1.Of or pertaining to the rhachis; as, the rhachidian teeth of a mollusk.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Most anterior teeth, especially rhachidian and innermost laterals always with slight signs of wear; total length 3 mm in a 7-mm male, width 0.4 mm.