"...Make thee my knight? My knights are sworn to vows / Of utter hardihood, utter gentleness, / And, loving, utter faithfulness in love, / And uttermost obedience to the King."
-- Lord Alfred Tennyson, Idylls of the King, 1872
They had to do with a pride in a man's courage and hardihood, courage and hardihood that could make of thefts, of murder, of crimes dimly guessed, wrongs no more reprehensible than a boy's apple-stealing.
-- Dashiell Hammett, "Ruffian's Wife," 1925
Hardihood came to English in the 1600s from the Old French hardir meaning "to harden" or "to make bold." This ultimately comes from the Proto-Germanic hardjan meaning "to make hard."