ROISTER Meaning of ROISTER in English [ 'rɔɪstə ]■ verb enjoy oneself or celebrate in a noisy or boisterous way.Derivatives~er noun~ous adjective OriginC16: from obs. ~ '~er', from Fr. rustre 'ruffian'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004