Real Dictionary

Senorita
You use Senorita when you are speaking to or referring to a young, unmarried Spanish-speaking woman.

señorita in American English
Miss
noun: a Spanish term of address equivalent to Miss, used alone or capitalized and prefixed to the name of a girl or unmarried woman

señorita in British English
noun: an unmarried Spanish or Spanish-speaking woman: a title of address equivalent to Miss when placed before a name or madam or miss when used alone
noun: Spanish term of address equivalent to madam or Miss