host  
 noun uk/həʊst/ us/hoʊst/
  (PERSON WITH GUESTS)      
 B2 [ C ] (female also hostess)主人,东道主 
someone who has guests
  We thanked our hosts for a very enjoyable evening. 我们感谢主人让我们度过了一个愉快的夜晚。 
 The local language school is advertising for host families (= families people stay with when they are visiting another country). 当地的语言学校正在招募能接待外国来访者的家庭。 
 - More examples
 - Our host was wearing a clown costume.
 - So please give a big hand to your host for the evening, Bill Cronshaw!
 - Would you mind playing host ?
 - After dinner our host said, "Shall we retire to the drawing room?"
 - She thanked the hosts for their hospitality.
 
  (ON TELEVISION)      
 C2 [ C ] (female also hostess)(电视或广播节目的)主持人 
a person who introduces guests and performers, especially on television or radio
  Our host for tonight's show is Jimmy Fallon. 我们今晚节目的主持人是吉米‧法论。 
 Synonyms: compere emcee 
 - More examples
 - He's the host of a popular game show.
 - The host of a well-known talk show was arrested by police last night.
 - Auditions are being held to find the host of a new music show.
 - One of the guests insulted the host live on camera.
 - He's now the host of his own show on Channel 4.
 
  (FOR AN EVENT)      
  [ C ]主办方,东道主 
a place or organization that provides the space and other necessary things for a special event
  Japan is playing host to the next international conference. 日本将主办下一次国际会议。 
 the host nation for the next World Cup 下届世界杯的主办国 
 - More examples
 - In 1992, Britain played host to the first multi-racial South African team to visit these shores.
 - Paris will be the host of the next Olympics.
 - The host city was congratulated for their staging of the event.
 - The host nation qualifies automatically for the event.
 - The city plays host to the party conference in September.
 
  (ANIMAL/PLANT)     
  [ C ] biology specialized寄主,宿主 
a plant or animal that another plant or animal lives on as a parasite
   (A LOT)     
 a host ofC1 许多,大量
a large number of something
  There's a whole host of reasons why he didn't get the job. 有一大堆理由可以解释他为什么没有得到那份工作。 
 Their clients were using a host of different advertising methods.
 We read works by Swift, Kipling, Waugh, and a host of lesser writers.
 Use of these fuels creates a host of environmental and human health problems.
 There was a whole host of reasons why the business failed.
   (CHURCH)    
 the host[ S ] religion specialized 圣体(基督教圣餐仪式中用的面饼)
the holy bread that is eaten at Communion (= a Christian religious ceremony)
   (INTERNET)     
 [ C ]提供网络支持的公司(主机) 
a company that hosts a website on the internet
 host  
verb [ T ] uk/həʊst/ us/hoʊst/
  (EVENT)      
 C1 主办(为一活动提供举办场所和其他必需品)
to provide the space and other things necessary for a special event
  Which country is hosting the next Olympic Games? 哪个国家将主办下届奥运会? 
 - More examples
 - South Africa has submitted an application to host the World Cup.
 - Paris is bidding to host the next Olympics.
 - Sydney made a successful bid to host the Olympic Games.
 - The city is hosting the winter Olympics next year.
 - The town has been hosting the annual event for the last 24 years.
 
  (TELEVISION SHOW)      
  主持(电视或广播节目)
to be the host of a television or radio programme
  to host a show/programme 主持节目 
 Synonyms: compere emcee 
   (WEBSITE)      
 为(网站)提供软硬件支持
to provide the computer hardware and software that allows a website to exist on the internet
  I've written my website, now I just need to find a company to host it. 我已经写好自己网站的内容了,现在只需找一家公司为它提供软硬件的支持。