lobule UK /ˈlɒb.juːl/US /ˈlɑb.jul/ noun4 •Diminutive of lobe. •A small lobe; a subdivision of a lobe. •In liverworts with bilobed leaves, the smaller of the two lobes, sometimes modified to form a sac. •A tongue-like structure opposite the scutellum in grasses; the epiblast. formslobules