unchangeable /ʌnˈt͡ʃeɪnd͡ʒəbəl/adjective 1noun 1forms 3 adjective1 •Not changeable; incapable of being changed or of changing; immutable.Psychologists call this the entity theory of intelligence, which is simply the belief that ability is innate and unchangeable. — 2025 noun1 •Something that cannot be changed. formsunchangeables · more unchangeable · most unchangeable