Referring to American people who have an impression of themselves and their country as being some how superior to the rest of the world. It is an ethnocentric belief that their culture, politics, economics, society and generally all aspects of the country as so amazingly awesome. Thus, the behaviour of someone who has a big dick. It is also the attitude for which Americans are often disliked by other nations and groups of people around the world. Rather than take a humble, helping, culturally sensitive approach to interaction with other people and international relations; the big dick syndrome often causes tensions with other peoples due to how non-Americans are assumed to be wrong or inferior. Also includes a denial of any possibility of making a mistake and an inability to apologize - leading to a lack of credibility and faith in the US by other peoples. The sydrome comes in part from the belief that the military's might is sufficient to over-rule any opposition. This might is used often in contrary to the principles of democracy, self determination and freedom which the country was founded upon.
American Big Dick Syndrome has been demonstrated in Iraq, Vietnam, the alleged "fair-trade" (two for me, none for you) much of Latin American politics, ignoring the United Nations, etc.
The mispronounced, over use of slang, often poorly educated twang, abortion of the use of the proper English language. It often includes mis-spelled words such as color (actually spelt colour by those who invented English). Depending on the geographic region, the accent commonly changes the sound of the vowels and where the emphasis is placed on words. For example, "police" with emphasis on the vowel "I" changes to an emphasis on the "O". In addition, the grammar includes words are blended together rather than properly pronouncing individual words. "You" (used in the plural) becomes "You all" and is shortened to "Y'all" which isn't acutally a word in any language. In large groups this can become "all, y'all" a redundant form.
An American accent mis-pronouncing the phase "You will get arrested by the police" sounds like "All y'all gonna get busted by the PO-lice."