THICK SKIN

The definition of thick skinned is someone who is not easily upset or insulted and who can take criticism well. 
An example of thick skinned is a person who is insulted and simply says "whatever, I don't care."

You think you heard that expression before? You probably did, on the radio or even on TV. It is part of a song by Sia.

 

So, are you a thick skinned type of person? Or are you easily offended?

The Final Nail In The Coffin

An event that causes the failure of something that had already started to fail.e.g.: This latest evidence could be the final nail in the coffin for Thomas' case.
VOCABULARY HELPERS:                                                                           NAIL

COFFIN

THE FINAL NAIL IN THE COFFIN ( or ANOTHER NAIL IN THE COFFIN)

CUT TO THE CHASE

Meaning: 1.Leave out all the unnecessary details and just get to the point. 2. Come to the point.

A Shot In The Arm

Meaning: 

A stimulus.

Origin:

This expression derives from the invigorating effect of injecting drugs. A shot is of course US slang for an injection, either of a narcotic or medicinal drug. That term has been in use since around the beginning of the 20th century; for example, this piece from the San Francisco Chronicle Supplement, October 1904:

"I varied hardly a minute each day in the time of taking my injection. My first shot was when I awoke in the morning."

'A shot in the arm' came soon afterwards and the first mention of a figurative use of it in print that I can find is from

the Maine newspaper The Lewiston Evening Journal, January 1916:

The vets can give politics a shot in the arm and the political leaders realize it.