What is another word for "unbidden"?

Roget's Thesaurus (1911) lists these synonyms for "unbidden": accord, autocratic, bid, casual, choice, deliberately, discretion, discretional, discretionary, est, free, good, head, intended, intentionally, man, minded, muss, one, optional, original, out, own, pleasure, prepense, pro, proper, purposely, sic, spontaneous, stet, volitient, volitional, volitive, voluntarily, voluntary, was, will, willful, willing.