bugger
n.n. a person who is very annoying or a thing that causes trouble. It is a very informal and slightly rude way to talk about someone or something.
n. a person or thing that causes annoyance, trouble, or difficulty. Highly informal and often considered vulgar; frequently used as a mild expletive in British English.
What a bugger this weather is.
I can't find the keys again; this is the third time this week they've been a total bugger.
The software update was a total bugger, causing the entire server to crash and losing several hours of unsaved work for the development team.
From Middle English bougre (“heretic”), from Old French bougre, from Medieval Latin Bulgarus (“Bulgar”), from Old Church Slavonic блъгаринъ (blŭgarinŭ, “Bulgarian”), used in designation of heretics (especially the Bogomils, who arose around the 10th century AD in the First Bulgarian Empire), to whom various sexual practices such as anal sex were ascribed. Doublet of Bulgar.
From bug (noun) + -er.