The Spanish word 'serrado' (meaning 'sawed') comes from the Spanish verb 'serrar' (meaning 'to saw'), which itself derives from the Latin verb 'serrare' (meaning 'to saw'). The Latin verb 'serrare' was formed from the Latin noun 'serra' meaning 'saw' (the tool). The '-ado' ending is the past participle suffix in Spanish, indicating that something has been sawed or cut with a saw.

Some related Spanish words include 'sierra' (meaning 'mountain range' or 'saw'), which comes from the same Latin root 'serra'. The word 'sierra' originally referred to the jagged, saw-like appearance of mountain ranges. Another related word is 'aserrar' (to saw), which is formed by adding the prefix 'a-' to 'serrar'.

The English word 'sierra' is borrowed directly from Spanish and shares the same Latin origin. We use it primarily to refer to mountain ranges, as in 'Sierra Nevada'. The word 'serrated', meaning having a notched edge like a saw, also comes from the same Latin root 'serra'. You can see this connection clearly in serrated knives, which have a saw-like edge.