English主要词典
obligatory
Universal Words
adjective
1 ~ (for sb) (to do sth) (formal) that you must do because of the law, rules, etc.
SYNCOMPULSORY:
It is obligatory for all employees to wear protective clothing.
2 (often humorous) that you do because you always do it, or other people in the same situation always do it:
In the mid 60s he took the almost obligatory trip to India.
