Linguetronix

limpio - clean (adj.)

I like this word since it sounds like it would be related to "limp" in English, but it means something completely different! The opposite of 'limpio' is 'sucio'. For example,

El cuchillo está limpio

(The knife is clean)

Hope you enjoyed that short lesson!

It almost seems like the author has invented the unimportant words himself, I haven't heard of any!

As for the important words, while most people here seem to agree with the whole list, I take issue with the following words:

Sousveillance, Precariat and Binge-watching

I haven't heard any of them being used and some of them sound like they're trying really hard to be made into legitimate words. Putting these words in the other list would have done them justice.

Fought tooth and nail - meaning to fight very hard, very doggedly.

He took a dagger to the heart - to receive a huge blow, mostly shocking emotional news.

I have a few more to add.

He was beaten black and blue - he was beaten very badly/He was bruised all over.

To tell a white lie - to tell a harmless lie.

Raise the white flag - to surrender.