In a coercive manner; by means of force or compulsion; against someone's will.
From coercive + -ly, the English adverbial suffix. This creates the standard adverb form describing how an action is performed or how something is done.
The adverb 'coercively' is much more common in actual writing than 'coercibly,' showing how English has built-in preferences for word formations. Speakers instinctively combine 'coercive' (common adjective) with '-ly' rather than trying to make an adverb from 'coercible' (less common).
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