bluebottle b looh baw tuhl n an annual Eurasian plant cultivated in North America having showy heads of blue or purple or pink or white flowers n blowfly with iridescent blue body; makes a loud buzzing noise in flight Usage(s) The flies used are the bluebottle (Calliphora erythrocephala) and the greenbottle (Lucilia caesar). You have to put your lips together and make a sound like bluebottle flies buzzing on the window. A later observation: that bone infections could be cured by the use of bluebottle fly maggots. Synonym(s) cornflower bachelor's button Centaurea cyanus Calliphora vicina