Definisi dalam bahasa Inggris
optional
/'/A/p/S//@/n/-/l /adjective (a)
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possible but not necessary; left to personal choice (adj.all)
Antonim: obligatory
Sumber: wordnet30
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Involving an option; depending on the exercise of an option; left to one's discretion or choice; not compulsory; as, optional studies; it is optional with you to go or stay. (adjective)
Sumber: webster1913