Opposite of optional - Answers

Direct Opposite of optional

obligatory, incumbent on(predicate); INSERT INTO opposite (oppositeid, word1, word2, link, word_soundex) VALUES indispensable, bounden, indispensable, prerequisite, mandatory, compulsory, incumbent on(p), required, imposed, obligatory, de rigueur,

Indirect Opposite of optional

mandatory, bounden, indispensable, imposed, required, compulsory, incumbent on(p), de rigueur, prerequisite,