字義:
The presiding officer of a meeting, organization, committee or event.
主席；主持一個會議、組織、委員會或是事件的官員。
Different voices easily heats up debate. Opinions in a MUN conference can be as diverse and piercing. Let alone by themselves, delegates representing different countries is very likely to yell at one another for different aspects of the issue, letting the conference out of control. Therefore, a Chairperson (Chair), along with one or more Assistant Chairs sits in front and take full control of MUN conferences. The Chair is authorized to keep the whole committee in order, with help from Assistant Chairs.
歧見易紛爭，在模聯會議中更是如此。一個沒有主席的會議常常一片混亂，因為每個不同國家代表會對同一個議題有不一樣的看法，甚而極有可能會在激動的時候對對方大吼。因此，在所有的模聯會議中，都會有一個主席和一個或以上的副主席。主席被授權負責維持整個委員會的秩序，而副主席的職責則是協助主席。
例句：
"Honorable Chair and my distinguished fellow delegates, the delegate of Mexico believes that the proposal made by delegate of Burkina Faso is reasonable enough and worth discussing. Thank you, Chair" the delegate stated at the beginning of his speech.
"尊貴的主席和我傑出的與會代表同事們，墨西哥的代表相信，由布吉納法索代表所提出的提議案是相當合理的且值得討論的。謝謝你，主席" 墨西哥代表一開始陳述著。
"The Chair now announces the floor officially open" is a common statement a Chair uses to begin a conference.
"主席現在宣布正式開放發言權"是模聯會議主席常採用的開場句。
