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 Portuguese that is not attested[1], but which left an inherited descendant in Galician. See also outeiro, a related word.

Alto

alto (feminine alta, masculine plural altos, feminine plural altas, comparable, comparative mais alto, superlative o mais alto or altíssimo, diminutive altinho, augmentative altão)

From Latin altus, ultimately of Proto-Indo-European origin. The form alto represents a pronunciation influenced by the most learned layers of the language, and is not the normal phonetic result expected in a naturally inherited word. Cf. the now archaic form oto, which was used more often in Old Spanish and is the form of the word that was completely popularly inherited, preserved in some toponyms/placenames[1], and its derivative otear and the rare or regional otar[2]. Compare also archaic Galician outo (versus the standard alto today). See also the related Spanish otero (and Portuguese outeiro). 041b061a72