To reduce, diminish, or make smaller in size, amount, or importance.
From dis- (prefix meaning 'reverse') + augment (from Latin augmentare, 'to increase'). This word creates the opposite meaning of augment and is quite rare in modern usage.
This is a scholarly, rarely-used word that shows how English's dis- prefix can theoretically create opposites for almost any verb—but it usually doesn't catch on. 'Diminish' or 'reduce' work better, so 'disaugment' remains mainly in dictionaries.
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