1570s, "of the nature of a mandate," from Late Latin mandatorius "pertaining to a mandator," from Latin mandatus, past participle of mandare (see mandate (n.)). Sense of "obligatory because commanded" is from 1818.
权威例句
1. In a case of premeditated murder a life sentence is mandatory.
蓄意杀人依法要判无期徒刑。
2. It is mandatory for blood banks to test all donated blood for the virus.
血库必须检查所有捐献的血是否含有这种病毒。
3. Is the appointment of worker - directors to be mandatory?