Just the facts:

SCATHING Definition & Meaning - Merriam-Webster

Scathing comes from Old Norse word skathi (noun), skatha (verb); and is related to Dutch and German word schaden (verb). 

The earliest known use of the adjective "scathing" in English is from 1794, with evidence found in the writings of Samuel Taylor Coleridge, poet, critic, and philosopher. The word is formed within English by derivation from the verb "scathe". The verb "scathe" itself has an earlier origin, with its first known use in Middle English around 1175. 

Examples of "scathing" in a sentence:  
"Joan gave Robert a scathing look and did not reply after he'd asked a very personal question." 
"I read a most scathing review of his latest book" 
"He unleashed a scathing attack on his former boss after being fired." 
"The book was a scathing attack on the media establishment." 
"His actions and decisions have also brought scathing criticism."
"May's change of side made him many bitter enemies, and he is the object of scathing condemnation from many of his contemporaries." 
"He didn't want to try to interpret the look or await her scathing return, not when he needed to find a place for them go to."