misdemean

With a reflexive pronoun: to cause (oneself) to behave badly.

he misdemeaned himself

[Y]ou that beſt ſhould teach vs, / Haue miſdemean'd your ſelfe, and not a little: / Tovvard the King firſt, then his Lavves, in filling / The vvhole Realme, by your teaching & your Chaplaines / (for ſo vve are inform'd) vvith nevv opinions, / Diuers and dangerous; vvhich are Hereſies; / And not reform'd, may proue pernicious.

To misbehave.