costula
noun
cos·tu·la
ˈkäschələ,
-styə-
variants or costule
-schəl,
-styəl
plural costulae
-ˌlē,
-ˌlī
or costules zoology
: a small ridge (as one of those that make up the sculpture of a mollusk shell)
costulation noun
ˌ⸗⸗ˈlāshən
plural -s
Word History
Etymology
New Latin costula, from Latin costa rib + New Latin -ula