来自古诺斯语 snagi,晾衣架，挂衣钩。引申词义树桩，树枝，后用于指河道中被河水浸没的 树桩，暗桩，因而引申比喻义潜在问题，困难，障碍，引申词义被勾住，被挂住等。

1. There is just one small snag—where is the money coming from?

只有一个小问题—钱从哪儿来？

2. The only snag is, I can't afford it!

惟一的困难是, 我付不起这钱!

3. It is to be expected that an experiment will sometimes run into a snag at first.

开始试验时有时不很顺手,也是很自然的.

4. The school deals exclusively with children of high academic ability. There is a snag though, it costs £9,600 a year.

这所学校只招收学习能力强的孩子，不过还有个小问题——它每年的学费高达9,600英镑。

5. A police clampdown on car thieves hit a snag when villains stole one of their cars.

警方打击偷车贼的行动遭遇了一点小挫折：匪徒偷走了一辆警车。