Definify.com
Webster 1913 Edition
Conchoidal
Con-choid′al
,Adj.
[Cf. F.
conchoïdal
.] (Min.)
Having elevations or depressions in form like one half of a bivalve shell; – applied principally to a surface produced by fracture.
Webster 1828 Edition
Conchoidal
CONCHOIDAL
,Adj.