1. [adj]  not tempered; "individualism untempered by social responsibilities"
2. [adj]  not brought to a proper consistency or hardness; "untempered mortar"; "untempered steel"
3. [adj]  extravagant or extreme; "the inhumanity of his untempered principles"- M.S.Dworkin

UNTEMPERED is a 10 letter word that starts with U.