Is America an Empire

I have heard it said before and it was recently brought up in a debate that America is an "empire". I don't like the term for several reasons, because it seems to me that America is anything BUT an empire, so I looked it up.

Here are the 10 definitions of "empire" offered up by dictionary.com

1. a group of nations or peoples ruled over by an emperor, empress, or other powerful sovereign or government: usually a territory of greater extent than a kingdom, as the former British Empire, French Empire, Russian Empire, Byzantine Empire, or Roman Empire.
2. a government under an emperor or empress.
3. (often initial capital letter) the historical period during which a nation is under such a government: a history of the second French empire.
4. supreme power in governing; imperial power; sovereignty: Austria's failure of empire in central Europe.
5. supreme control; absolute sway: passion's empire over the mind.
6. a powerful and important enterprise or holding of large scope that is controlled by a single person, family, or group of associates: The family's shipping empire was founded 50 years ago.
7. (initial capital letter) a variety of apple somewhat resembling the McIntosh. –adjective
8. (initial capital letter) characteristic of or developed during the first French Empire, 1804–15.
9. (usually initial capital letter) (of women's attire and coiffures) of the style that prevailed during the first French Empire, in clothing being characterized esp. by décolletage and a high waistline, coming just below the bust, from which the skirt hangs straight and loose.
10. (often initial capital letter) noting or pertaining to the style of architecture, furnishings, and decoration prevailing in France and imitated to a greater or lesser extent in various other countries, c1800–30: characterized by the use of delicate but elaborate ornamentation imitated from Greek and Roman examples or containing classical allusions, as animal forms for the legs of furniture, bas-reliefs of classical figures, motifs of wreaths, torches, caryatids, lyres, and urns and by the occasional use of military and Egyptian motifs and, under the Napoleonic Empire itself, of symbols alluding to Napoleon I, as bees or the letter N.

Which, if any, of these do you think applies to the United States?