ª is the feminine ordinal indicator, used in Portuguese and Spanish. It is a superscript a, which is the feminine adjective ending. "Primera" (meaning "first"), for example, is written as 1ª or 1a, the same way it is written in English as 1st.
The following requires the presence of certain fonts, likely to be present in a computer with Windows installed.
|Feminine ordinal indicator in different fonts|
ª ª ª ª ª ª ª
See also: º