The Spanish word 'tumbado' comes from the verb 'tumbar' meaning 'to knock down', which itself is derived from the onomatopoeic root 'tumb-' that imitates the sound of something falling. The word is formed by combining this root with the verb suffix '-ar' to create 'tumbar', and then adding the past participle suffix '-ado' to form 'tumbado', meaning 'knocked down' or 'lying down'.

This is a great example of how Spanish, like many languages, creates words that mimic the sounds they represent. The 'tumb-' sound effectively captures the heavy, dull thud of something falling or being knocked over.

Some related Spanish words include the noun 'tumba' (tomb, grave), which shares the same root and evokes the idea of lying down or falling down into the earth. There's also 'tumbo' (tumble, fall), which directly relates to the action of falling or rolling over.

While not directly related etymologically, English speakers might find it helpful to associate 'tumbado' with similar-sounding English words like 'tumble' and 'tomb', which share some conceptual overlap in terms of falling or lying down, though these connections are coincidental rather than etymological.