barfly is an American compound of bar (drinking establishment) and fly (insect), likening the habitual drinker to a fly hovering around a bar; first attested early 20th century. Morphologically, the word is transparent as a compound: its parts remain visible in the modern spelling, while the older history of those parts supplies the deeper ancestry. In modern use, the noun sense is "a person who frequently spends time drinking in bars", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as bar, fly, showing how the same base continues to support neighboring English vocabulary.