interchangeably (adv.)
in turn, in exchange, reciprocally
1H4 III.i.77 [Mortimer to all, of the agreement] being sealed interchangeably [i.e. with each person having a copy signed by the others]
R2 I.i.146 [Mowbray to King Richard] I ... interchangeably hurl down my gage
R2 V.ii.98 [York to Duchess of York] A dozen of them here have ... interchangeably set down their hands / To kill the King at Oxford