A first-course dish; appetizer.
Several salads on the menu proved to be better appetite arousers than some of our starter choices. (New York Times, July 14, 1991. Note interesting use of the word arouser.)/While there’s a slew of appetizers and salads to try as starters, the small plates make for a nice way to try and share more dishes. (TheDay.com [New London, CT], April 21, 2011)
notoneoffbritishisms.com 
Again, as a New York City area native who has been in restaurants since infancy, I have heard starter used interchangably with appetizer my entire life. Now that I think about it, I tend to use the phrase “I’ll have the _____ to start” or “….for starters”. I rarely say appetizers, and it is not a deliberate pretension to cool Brit-ness, as my frequent use of other NOOBs tends be…
Like so many of these preposterous posts, appetizer is an Americanism of starter – starter being the phrase used originally. Personally I have no problem with anyone deciding to use an alternate phrase for something if they so wish, but to claim the original is incorrect somehow is a tad cheeky. It is intersting to note that the Americanism in question here is not only using a different word, but spelling it differently as well – the English version being appetiser.
@Daniel:
Wow: your pomposity is exceeded only by your ignorance.
“Appetizer” (thus spelled) appears in Sir Walter Scott’s “The Abbott” (1820) and Lord Byron’s “Don Juan — notes to Canto V” (1821). I suppose they must have been Americans?
I don’t know exactly when “starter” to mean “first course of a meal”, came into use, but in a few searches I was unable to find anything earlier than 1950. Perhaps someone with free access to the online OED could confirm.
As requested: OED’s first cite for “starter” is 1966, with this quote from New Society in 1968: “The first course of a meal is sometimes called a ‘starter’, which is perhaps not so much non-U as jargon.”
This is really interesting, I wasn’t aware that ‘starter’ wasn’t as frequently used in America. I don’t want to speak on behalf of all BrE speakers but to me an ‘appetiser’ has a closer semantic meaning to ‘hors d’œuvres’.
I have noticed of late more use in AmE of the phrase ”For starters” when referring to the first line of arguments that a person wishes to make