austere
Pronunciation: /ɒˈstɪə, ɔː-/
adjective ( austerer, austerest)
- severe or strict in manner or attitude: he was an austere man, with a rigidly puritanical outlook
- (of living conditions or a way of life) having no comforts or luxuries: conditions in the prison could hardly be more austere
- having a plain and unadorned appearance: the cathedral is impressive in its austere simplicity

Origin:
Middle English: via Old French from Latin austerus, from Greek austēros 'severe'