er ‧ rant /ˈerənt/ BrE AmE adjective [only before noun] old-fashioned
[ Date: 1300-1400 ; Language: Latin ; Origin: present participle of errare ; ⇨ ↑ err ]
behaving badly, usually by not obeying your parents or not being faithful to your husband or wife:
an errant wife
their errant son