obliterate ⇒ 他的伟大功绩不可磨灭。 Tā de wěidà gōngjì bùkě mómiè. → His huge achievements cannot be obliterated.
磨炼
steel
磨蹭
( 摩擦 ) rub ... lightly
磨难
hardship
磨洋工
dawdle over one's work
临阵磨枪
leave things until the last moment ⇒ 平时要努力,靠临阵磨枪不行。 Píngshí yào nǔlì, kào lín zhèn mó qiāng bùxíng. → You should work hard all the time, and not leave everything until the last moment.