alto

From Old Galician-Portuguese alto, from Latin altus, ultimately of Proto-Indo-European origin. This form is likely a semi-learned term, or was influenced by learned elements of the language and uses such an orthography, as with Galician and Spanish alto (which have popularly inherited variants outo and oto, respectively). There was once likely an *outo in Old Galician-Portuguese that is not attested, but which left an inherited descendant in Galician. See also outeiro, a related word.