señorita

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Used as a courtesy title before the surname or full name of a girl or unmarried woman in a Spanish-speaking area.
• noun Used as a form of address for a girl or young woman in a Spanish-speaking area.
• noun A Spanish or Spanish-speaking unmarried woman or girl.

from The Century Dictionary.

• noun A young lady; in address, miss; as a title, Miss: in Spanish use.
• noun In ichthyology, a graceful little labroid fish of California, Pseudojulis or Oxyjulis modestus.
• noun A Californian fish, Halichæres semicinctus.

from the GNU version of the Collaborative International Dictionary of English.

• noun A Spanish title of courtesy given to a young lady; Miss; also, a young lady.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A young woman in or from a Hispanophone community.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a Spanish title or form of address used to or of an unmarried girl or woman; similar to the English `Miss'