(1)主人(person who entertains sb else as his guest，usu in his own house)[C]：act as～to one's parents' friends 像主人一样招待自己父母的朋友;the～city/nation/country for the next Olympic Games下届奥林匹克运动会的东道主城市/国家/国家; 〖反〗guest;

(2)(广播，电视的)节目主持人(person who introduces other performers，such as those on a TV show)[C]：the～on evening's show晚间电视节目主持人;

(3)旅(酒)馆老板(inn-keeper，hotel-keeper)[C]：Your～，John Smith，hopes your stay at the hotel will be a pleasant one. 旅店老板约翰·史密斯先生希望你在旅店居住得愉快。

(4)宿(寄)主(animal or plant on which some lower form of lives is living as a parasite)[C]：～organisms(动植物的)寄生有机体;(apple-tree) act as～s to mistletoe(苹果树)作为懈寄生的宿主;(oak-tree) be the～of the mistletoe that grows on it (橡树)是在其上面生长的懈寄生的宿主;

be/play host to sb招待……：The hotel (university) is～to a group of Russians (this year's conference). 这个旅店招待一批俄国人(这所大学召开今年的协商会议)。

→′hostess n女主人;

vt 作主人招待，主办，主持(act as host of (a party，friendly meeting，TV show，etc))[T+n](infml)：～the games/Olympic Games/show/garden party主办这次比赛/奥林匹克运动会/表演/游园会