1.without any rational explanation or apparent sense
1.unpredictable character, mysterious smile , declaration without rhyme or reason.
难以捉摸的性格，神秘的微笑，莫名其妙的声明。
2.The brothers discussed without rhyme or reason and decided to go to big city to make a living.
不知道怎么一来，兄弟俩商量好，到外面大城市里去闯荡一下，找一条活路。
3.The watches complained about frequently stopped working without rhyme or reason.
所提到的手表经常莫名其妙地停止走动。
4.Dogs only bite your body, but cats will nibble away at your soul. Of course this is a superstition, but it is not without rhyme or reason.
狗只能咬你的身体，猫却会蚕食你的灵魂，这当然是迷信，但是也很有来由。
5.Some youngsters may commit crimes without rhyme or reason.
一些年轻人会无缘无故的犯罪。
6.Nothing in the world it is without rhyme or reason. Love, nor the hate it is without rhyme or reason. Mao Zedong.
世界上没有无缘无故的爱，也没有无缘无故的恨。——毛泽东。
7.e. g. Don't take others' money without rhyme or reason.
不要无缘无故拿别人的钱。
8.She got angry without rhyme or reason.
她莫名其妙地生起气来。
9.If have person it is without rhyme or reason. Smile at you, it must be for some reason. -- Ma Changshan
如果有个人无缘无故地对你微笑，那一定是为了某种缘故。——马长山
10.Always felt a wave of emptiness without rhyme or reason
总是莫名其妙感到一阵的空虚