Porteño Spanish is the dialect of caste-sha-no (castellano) spoken in Buenos Aires, Argentina and the surrounding areas. It is categorized by an Italian-like pronunciation and colorful Lunfardo slang.Browse Slang Dictionary
orphan; wild child
Alternatively spelled "wacho", this originally referred to a small animal left in the countryside without parents. It came to refer to children who were also orphans somewhat derogatorily. Today, it usually means someone who has attitude or a little wild.
"Tenés que ser un poquito wacho para bailar tango".
You have to have some attitude to dance tango.