Synonyms and related words :
artless, bluff, blunt, candid, childlike, confiding, direct, frank, guileless, ingenu, ingenuous, innocent, naive, open, openhearted, outspoken, plain, simple, simplehearted, simpleminded, sincere, single-hearted, single-minded, trustful, trusting, unguarded, unreserved, unsophisticated, unsuspicious, unwary,