obligatory
ob|liga|tory /əbl'ɪgətri, AM -tɔːri/
1 [ADJ]
If something is obligatory, you must do it because of a rule or a law.
Most women will be offered an ultrasound scan during pregnancy, although it's not obligatory...
These rates do not include the charge for obligatory medical consultations.
= compulsory
≠ optional
2 [ADJ] ADJ n
If you describe something as obligatory, you mean that it is done from habit or custom and not because the person involved has thought carefully about it or really means it.
She was wearing the obligatory sweater and pearl necklace.
= customary
1 [ADJ]
If something is obligatory, you must do it because of a rule or a law.
Most women will be offered an ultrasound scan during pregnancy, although it's not obligatory...
These rates do not include the charge for obligatory medical consultations.
= compulsory
≠ optional
2 [ADJ] ADJ n
If you describe something as obligatory, you mean that it is done from habit or custom and not because the person involved has thought carefully about it or really means it.
She was wearing the obligatory sweater and pearl necklace.
= customary