SaO

Sao is a term that can refer to several different uses, depending on context. In Portuguese-speaking regions, the word São (often written without diacritic in non-Portuguese texts as Sao) means Saint and is used as a prefix in place names and personal names. It appears in many city names such as São Paulo or São Luís, and in given names and surnames that honor a saint. The diacritic distinguishes meanings, but English-language texts frequently drop it, producing Sao.

In astronomy, SAO denotes the Smithsonian Astrophysical Observatory Star Catalog. This catalog provides identifiers for hundreds of thousands of stars and is used for cross-referencing in stellar research. The SAO designation system is still referenced in historical and some observational contexts, even as larger and more modern catalogs have expanded beyond it.

Beyond these uses, Sao may appear in written forms where the diacritic is unavailable or in contexts derived from Portuguese where São is transliterated as Sao. The meaning then depends on the surrounding text, typically relating to Saint names or to proper nouns associated with Lusophone culture.

Overall, Sao is a cross-domain term that can denote a linguistic prefix for Saint in Portuguese, a scientific catalog designation in astronomy, or a typographical variant of São in various texts. Because it spans languages, geography, and disciplines, disambiguation relies on context, making it a term with multiple, distinct senses rather than a single definition.