Roger Woodham replies:meeting/gathering/assembly/rally

Meeting (and meet) are the most generally and widely used from your list of four, Jianxin. Assembly (and assemble), gathering (and gather) and rally are more restricted in use.

meet (verb)

When two or more people meet, they come together or are brought together for some reason or they just happen to be in the same place and start talking:

• Where shall we meet this evening? ~ Let's meet under the clock at Waterloo Station.
  
  
• Have you met my dad? ~ No, I haven't. ~ Well, come and meet him. Dad, this is Martin. ~ Pleased to meet you, Martin.
  
  
• Representatives from the two countries will meet again in June to resume their talks.

meeting (noun)

A meeting is any event where a smaller or larger group of people come together to discuss something or to make a decision:

• Can I speak to Jane please? ~ No, I'm sorry she's in a meeting. ~ When will the meeting be over?
  
  
• Can we hold a meeting with everybody to discuss this, please? You can't make a decision without having a meeting first.
  
  
• Can you come to supper on Thursday? ~ I don't think so. I've got a meeting in the afternoon which is sure to go on till six or seven in the evening.

gather (verb)

When people or things gather somewhere, they come together for a particular purpose. They do not meet by chance:

• The storm clouds are gathering. It's going to rain soon.
  
  
• Can you see the birds gathering on that tree over there?
  
  
• We gathered around the camp fire and started singing folk songs.

When you gather things or pieces of information, you collect them with a particular purpose in mind:

• We went out to gather mushrooms in the woods.
  
  
• I need to gather as much information as I can so that I can write this report.

I gather means I understand in the sense that somebody has told me or I have read about this. As far as I can gather… is an expression meaning As far as I can find out…:

• I gather there will be no alcoholic beverages at the his party.
  
  
• As far as I could gather, he was trying to raise money by selling cars which had been stolen.

gathering (noun)

A gathering is a group of people who are meeting together for a particular purpose:

• There was an exclusive gathering of show-business people and footballers at Posh and Becks' Gucci and sushi garden party last Saturday.
  
  
• It was a friendly gathering. Everybody was in good humour and there was a lot of laughter.

assemble (verb)

Assemble is very close to gather in meaning in the sense of coming together for a particular purpose. It perhaps suggests a greater sense of organisation:

• They assembled / gathered in the school canteen after the exam to discuss how well they had done.

When we assemble things, we fit the different parts together to make a whole:

• He couldn't assemble the jigsaw without seeking the help of his older sister.
  
  
• If the police can assemble / gather enough evidence, they will arrest him for burglary.

assembly (noun)

Assemblies are usually larger gatherings of people who meet regularly for a particular purpose:

• The National Assembly voted to hold the first entirely free elections for over 20 years.
  
  
• The assembly of musicians was impressive. Over 300 were gathered together in the Festival Hall.

In a school, the assembly is a gathering of all teachers and pupils at a specified time in the school hall for matters that affect the whole school:

• The Junior School Assembly lasted for 45 minutes as there was a presentation on road safety.

You will also find assembly lines in factories where employees work on particular part of a product (e.g. a car) at a particular stage of its manufacture.

rally (verb)

When people rally, they unite to support something:

• He rallied his supporters in the hope that his party would win the election.

When someone or something rallies, it begins to recover from a weak position:

• The stock markets rallied and shares returned to their early morning values.
  
  
• After four days in bed, he rallied sufficiently to be able to sit out in an armchair.

If you rally at tennis, badminton or squash, you manage to keep the shots going with your partner for as long as possible without losing. Rally can also be used in this sense as a noun:

• It was one of the longest and most exciting rallies of the entire tournament.

rally (noun)

A rally is primarily a large public meeting that is held to show support for a cause or a political party. Rallies, like meetings, are held:

• Over ten thousand people held a rally in the square to demonstrate their support for international human rights.