Diffident

прилагательное 1) неуверенный в себе, застенчивый, робкий Синоним(ы): timid, shy, modest, bashful 2) недоверчивый Синоним(ы): distrustful 3) скрытный Синоним(ы): reserved

Большой англо-русский словарь

Diffident

adjective Etymology: Middle English, from Latin diffident-, diffidens, present participle of diffidere to distrust, from dis- + fidere to trust — more at bide 1. hesitant in acting or speaking through lack of self-confidence 2. archaic distrustful 3. reserved, unassertive Synonyms: see shydiffidently adverb

Merriam-Webster's Collegiate Dictionary