The Spanish word 'guiño' (meaning 'wink') comes from the Spanish verb 'guiñar' ('to wink'), which can be traced back to Late Latin. The verb evolved from the Late Latin 'cinnare' meaning 'to wink', which itself was related to the Late Latin word 'cinnus' referring to a facial gesture or wink. The modern Spanish noun 'guiño' was formed by adding the Spanish noun suffix '-o' to the verb stem 'guiñ-'.

The evolution from Latin 'cinnus/cinnare' to Spanish 'guiño' shows an interesting phonetic development where the initial 'c-' became 'g-' and the double 'nn' transformed into the Spanish 'ñ' sound, which is common in the evolution from Latin to Spanish words.

A common related Spanish word is the verb 'guiñar', which is actually the source of 'guiño'. While 'guiño' is the noun meaning 'a wink', 'guiñar' is the verb 'to wink'. Spanish learners might also encounter 'guiñada', which means 'a wink' or 'a blink' and is formed from the same root.

While there aren't any direct English cognates from the Latin 'cinnus', English speakers might find it helpful to think of similar gesture-related words like 'wink' or 'blink'. Though not etymologically related, these words serve the same function in English as 'guiño' does in Spanish.