1. Blowfly definition is - any of a family (Calliphoridae) of dipteran flies (such as the bluebottle or screwworm) that deposit their eggs especially on meat or in wounds.

2. : any of various stout dipteran flies (family Oestridae) with larvae parasitic in cavities or tissues of various mammals including humans Examples of Botfly in a Sentence Recent Examples on the Web On the third day, when Robey opened the cooler, there was still ice inside—but also a writhing pile of Botfly maggots all over the meat.