To balance or keep in equilibrium; to weigh or determine the weight of something.
From Old French apeser, from apo- (to, at) + peser (to weigh). The term evolved from weights and balances terminology into broader meanings of balance.
This is an archaic word that shows how closely 'weight' and 'balance' were connected in English—to 'apoise' something meant to put it on a scale and find its perfect equilibrium point.
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