1
- required by law or rules; compulsory法律（或规则）规定的; 强制的, 必须遵守的：
wearing helmets was made mandatory for pedal cyclists.
戴头盔已成为对骑脚踏车者的法律规定。
1.1
- of or conveying a command命令（性）的：
he did not want the guidelines to be mandatory.
他不想让这些指导原则带有强制性。
派生词
mandatorily
adverb词源
late 15th cent.: from late Latin mandatorius, from Latin mandatum 'something commanded'.