From dictionary.com
bug ( P ) Pronunciation Key (bg)
n.
A true bug.
An insect or similar organism, such as a centipede or an earwig. See Regional Note at lightning bug.
A disease-producing microorganism: a flu bug.
The illness or disease so produced: “stomach flu, a cold, or just some bug going around” (David Smollar).
A defect or difficulty, as in a system or design.
Computer Science. A defect in the code or routine of a program.
An enthusiasm or obsession: got bitten by the writing bug.
An enthusiast or devotee; a buff: a model train bug.
An electronic listening device, such as a hidden microphone or wiretap, used in surveillance: planted a bug in the suspect's room.
As far as a bug that only occurs with specific systems/configs, well, that could be system instability or whatever, or it could be some sort of compatibility issue that the game has with particular hardware. May end up being a video card driver issue (most often), but it could be a bug with the game.
