Dubya is a nickname for George W. Bush, the US president from 2001 to 2009. The W is his middle initial. In some southern United States speech, the letter W sounds like “dubya,” so people wrote the nickname that way — a bit teasing, a bit familiar. It belongs to news and talk from those years. You would not put it in a careful history essay unless you are showing how people spoke then. Though actually, many people outside the US never used this nickname at all; they just said his name, or a local short name for him. Informal only, and only that one man.

小布希（George W. Bush 的外號。台灣習慣叫小布希，對上他父親老布希；Dubya 是美國人用南方口音唸他中間名 W 的叫法。中國大陸寫「小布什」）