compulsory

adj

1. Required; obligatory; mandatory.

   “The ten-dollar fee was compulsory.”

   “They are entirely private concerns, established by individual teachers, and attendance upon them is no more compulsory than attendance on our dispensaries.”

   “Some might agree that membership in the firm is perhaps more compulsory than membership in a municipality, but balk at applying the analogy to the nation.”

   “Imagine a country where children do nothing but play until they start compulsory schooling at age seven. Then, without exception, they attend comprehensives until the age of 16. Charging school fees is illegal, and so is sorting pupils into ability groups by streaming or setting.”

   “I haven't booked, so I don't have a clue as to whether the service will be busy or not. Supposedly, reservations are compulsory, but I want to find out what would happen if you just turn up.”

2. Having the power of compulsion; constraining.

   “Such compulsory measures are limited.”

   “There will be financial and other incentives to encourage voluntary recruitment, but if that fails to find the numbers a compulsory nationwide call-up will be reconsidered.”

noun

1. Something that is compulsory or required.

   “Delobel and Schoenfelder failed to win the free dance, but they had built a big lead in the compulsories and the original dance.”