excommunicate, unchurch, anathemize, execrate, comminate, anathemise, damn, anathematise, bedamn, cuss, curse, anathematize, imprecate, maledict, accurse, swear, blaspheme.
Examples of usage:
Beshrew thyself, thou hoary dotard! - "Eugene Field, A Study In Heredity And Contradictions", Slason Thompson.
I speak as I think now, else I beshrew Even my next fellow's head! - "A Select Collection of Old English Plays, Volume I.", R. Dodsley.
Beshrew me if my eyes Will ever see it finished! - "Cyrano de Bergerac", Edmond Rostand.