Definition of Cladophora
: a genus (the type of the family Cladophoraceae of the order Cladophorales) of branched filamentous septate green algae usually firmly attached and with the branches arising from the upper end of the cells each of which has a reticulate chloroplast and several nuclei, the genus also being placed sometimes in the order Siphonocladales and sometimes in Ulotrichales
