demure
Pronunciation: /dɪˈmjʊə, dɪˈmjɔː/
adjective ( demurer, demurest)

Origin:
late Middle English (in the sense 'sober, serious, reserved'): perhaps from Old French demoure, past participle of demourer 'remain' (see demur); influenced by Old French mur 'grave', from Latin maturus 'ripe or mature'. The sense 'reserved, shy' dates from the late 17th century