The Spanish word 'lavado' comes from the verb 'lavar' meaning 'to wash', which itself derives from the Latin verb 'lavare' also meaning 'to wash'. 'Lavado' is the past participle of 'lavar', so it can function as an adjective meaning 'washed' or as a noun meaning 'washing' or 'laundering'.

This is a straightforward etymology where both the form and meaning have remained remarkably stable from Latin to modern Spanish, with the basic concept of washing being preserved throughout its history.

Some related and commonly used Spanish words include the basic verb 'lavar' (to wash), 'lavadora' (washing machine), 'lavandería' (laundromat), and 'lavaplatos' (dishwasher). All these words share the same root 'lav-' and are related to the concept of washing or cleaning.

While English 'wash' comes from a different root, there are some English words that share the Latin 'lavare' ancestry. These include 'lavatory' (a place for washing, now meaning bathroom), 'launder' (to wash clothes), and 'lotion' (a cleaning or moisturizing liquid). The word 'lavender' is also related, as this plant was commonly used in washing and bathing in Roman times.