backslide
v (pt, pp `backslid) [I]
lapse from good ways into one's former bad ways of living (从良好的生活方式)倒退(到以往不良的生活方式)
He's a reformed criminal who may yet backslide. 他是个经过改造的罪犯, 然而仍有可能故态复萌.
Our knowledge of the oceans a hundred years ago was confined to the two-dimensional shape of the sea surface and the hazards of navigation presented by the irregularities in depth of the shallow water close to the land.