akrasia akrasia /əˈkreɪzɪə , əˈkrasɪə / (also acrasia) ▸ noun [mass noun] mainly Philosophy the state of mind in which someone acts against their better judgement through weakness of will. – ORIGIN early 19th century : from Greek, from a- ‘without’ + kratos ‘power, strength’. The term is used especially with reference to Aristotle's Nicomachean Ethics.