besetting adjective 2noun 1forms 3 adjective2 •Deeply rooted; persistent.Rickie would not push himself. It was his besetting sin. — 1907 •Obsessive noun1 •The act of one who besets or attacks.I might also here tell you of the contests and battles that such are engaged in, wherein they find the besettings of Satan, above any other of the saints. — 1689 formsbesettings · more besetting · most besetting