SYN: Indistinctness, indistinction, uncertainty, doubt, confusion, promiscuousness.
ANT: Discrimination, distinctness, distinct, differentiation.
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KEY: Indispensable.
SYN: Necessary, essential, requisite, needful, expedient.
ANT: Unnecessary, unessential, inexpedient, dispensable.
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KEY: Indisposed.
SYN: Disinclined, unwilling, reluctant, sick, ailing.
ANT: Inclined, prompt, ready, willing, eager, desirous, sound, healthful.