frank·in·cense
noun/ˈfræŋkɪnsens/
/ˈfræŋkɪnsens/
[uncountable]- a substance that is burnt to give a pleasant smell, especially during religious ceremonies
乳香（点燃时散发出香味，尤用于宗教礼仪） Word Originlate Middle English: from Old French franc encens, literally ‘high-quality incense’, from franc in an obsolete sense ‘superior, of high quality’ (which also existed in English) + encens ‘incense’.