Obligatory Adjective Obligation Required Oblig·A·To·Ry ä Binding Law

oblig·a·to·ry
\\ə-ˈbli-gə-ˌtȯr-ē, ä- also ˈä-bli-gə-\\ adjective1. binding in law or conscience
2. relating to or enforcing an obligation
    a writ obligatory
3.

mandatory

, required
    obligatory military service
also : so commonplace as to be a convention, fashion, or cliché
    the obligatory death scene in opera
4.

obligate

1
• oblig·a·to·ri·ly \\ə-ˌbli-gə-ˈtȯr-ə-lē, ä- also ˌä-bli-gə-\\ adverb

obligatory
ob·liga·tory / E5bli^Etri; NAmE -tC:ri / adjective1. ~ (for sb) (to do sth) (formal) that you must do because of the law, rules, etc.
   (按法律、规定等)必须的,强制的
   SYN 

compulsory

:
   It is obligatory for all employees to wear protective clothing.
   所有员工必须穿防护服装。
   OPP 

optional

2. (often humorous) that you do because you always do it, or other people in the same situation always do it
   习惯性的；随大溜的；赶时髦的:
   In the mid 60s he took the almost obligatory trip to India.
   六十年代中期,他也赶时髦到印度一游。

obligatory adj.

oblig·a·to·ry
\əˈbligəˌtōrē, ˈäblə̇g-, -lēg-, -tȯr-, -ri, chiefly Brit |äblə|gātəri or -ā.tri\ adjective
Etymology: Middle English, from Middle French obligatoire, from Late Latin obligatorius, from Latin obligatus + -orius -ory
1.
 a. : demanded or required by existing obligations especially of a moral or legal nature; specifically : binding in law or conscience
 b. : imposing or constituting duty or obligation — often used with on or upon
  < obedience is obligatory on a soldier >
2. : relating to or used to create or enforce an obligation
 < a writ obligatory >
3. : having to be coped with (as by studying, acting, paying) : required
 < physical education is obligatory >
 < an obligatory contribution >

4. : 1b