cladoceranPronunciation: /kləˈdɒs(ə)r(ə)n/ ZoologyDefinition of cladoceran noun a minute branchiopod crustacean of the order Cladocera, which includes the water fleas. adjective relating to or denoting cladocerans. cladoceran in other Oxford dictionaries Definition of cladoceran in the US English dictionary