Incazelo yesichazamazwi yegama elithi "lacuna" iyigebe, isikhala esingenalutho, noma ingxenye engekho kudokhumenti noma umbhalo wesandla, noma ucezu olungekho noma igebe kulwazi. Kungase futhi kubhekisele emgodini omncane noma ukucindezeleka esakhiweni se-anatomical njengethambo noma izicubu. Igama lingasetshenziswa kokubili ngomqondo ongokoqobo nongokomfanekiso.
