malacology
noun
mal·a·col·o·gy ˌma-lə-ˈkä-lə-jē 
: a branch of zoology dealing with mollusks
malacological
ˌma-lə-kə-ˈlä-ji-kəl
adjective malacologist
ˌma-lə-ˈkä-lə-jist
noun 
Word History
Etymology
French malacologie, contraction of malacozoologie, from New Latin Malacozoa, zoological group including soft-bodied animals (from Greek malakos soft + New Latin -zoa) + French -logie -logy
First Known Use
1836, in the meaning defined above