means the firm belief that someone or something is reliable, honest, or safe — and the willingness to rely on them because of it

from From Old Norse 'traust,' meaning confidence or firmness, a cousin of words for 'strong' and 'true' — the same family that gives us 'tree' and German 'treu' (faithful). The thread that runs through all of them is the image of something solid enough to lean on: a sturdy trunk, a thing that holds. To trust someone was, at root, to treat them as load-bearing.