usurpously--prophetes.ai

† uˈsurpously, adv. Obs.^—1
[f. usurp v.: see -ous and -ly².]
By usurpation; usurpingly.

1461 Rolls of Parlt. V. 463/2 Takyng upon hym usurpously the coroune and name of kyng.

Oxford English Dictionary