(1)主债务(→principal debt)

(2)主要义务
即主要合同义务，指基于当事人的主要缔约目的而产生的义务。例如，在买卖合同中卖方的主要义务是向买方转移标的物的所有权。

• collect on delivery/C.O.D.
• collector/collr.
• Collector-General
• collector of births and burials
• collector of customs
• collector of decedent's estate
• collector of the port
• collega
• collegatarius
• collegatary
• college
• college education
• college fraternities
• College of Advocates
• College of Arms
• College of Justice
• collegia
• collegialiter
• collegiate chapter
• collegiate church
• collegium
• collegium ammiralitatis
• Collegium est societas plurium corporum simul habitantium.
• collegium illicitum
• collegium licitum