̷ ̷ˈ ̷ ̷ ̷ ̷əm noun
( plural osphra·dia -ēə)
Etymology: New Latin, from Middle Greek osphradion nosegay, diminutive of Late Greek osphra smell; akin to Greek ozein to smell — more at odor
: a single or paired sense organ connected with one of the visceral ganglia and situated near the gill of most aquatic mollusks that is supposed to be alfactory or to test the purity of the water passing to the gills