means Free from harm or risk, or able to be trusted not to cause it — and also, as a noun, the sturdy lockable box where you keep what you can't afford to lose.

from From Old French 'sauf' ('unharmed, safe'), itself from Latin 'salvus' ('uninjured, whole, in good health') — a cousin of 'salus' (health, welfare), the same root that gives us 'salvation' and 'salute.' The thread running through all of them is wholeness: to be safe is to come through intact. The noun for the strongbox arrived later, borrowed from the same family — a thing whose whole job is keeping its contents whole.