sb who is romantically involved with sb already in a committed relationship / the other woman / the other man / third person / third party (in dispute) / disinterested party / number three in a list
(after a verb or adjective) one who (is) ... / (after a noun) person involved in ... / -er / -ist / (used after a number or 後|后[hou4] or 前[qian2] to refer to sth mentioned previously) / (used after a term, to mark a pause before defining the term) / (old) (used at the end of a command) / (old) this
(prefix indicating ordinal number, as in 第六[di4 liu4] "sixth") / (literary) grades in which successful candidates in the imperial examinations were placed / (old) residence of a high official / (literary) but; however / (literary) only; just