To make firm or to establish with certainty; an archaic term meaning to strengthen or confirm.
From 'en-' (to cause to be) combined with 'firm.' The prefix converts 'firm' (stable, strong) into a verb meaning to make something firm or solid.
This archaic verb nearly vanished from English, replaced by 'confirm' and 'solidify,' but it persists in legal documents and old texts as a way to say 'make this absolutely certain and binding.'
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