להכפיש

In modern Hebrew, להכפיש means to make dirty. It is usually used on the context of a reputation, as in להכפיש את שמו. 

The word appears in one place alone in Tanach:

וַיַּגְרֵ֤ס בֶּֽחָצָץ֙ שִׁנָּ֔י הִכְפִּישַׁ֖נִי בָּאֵֽפֶר׃ 

He crushed my teeth with gravel; He *buried* me in ashes. [Eichah 3-16] 

Some understand it to mean to *bury*. This is related to the word כבש [almost the same as כפש] which also means to immerse [like food in vinegar in order to preserve it]. כבש is also to conquer [which is of course related to the previous definition. In both cases you are "subduing" in a sense]. 

But others understand it to mean to *make dirty*. From there is the contemporary usage.  

[This is discussed in לשוננו - אדר ב' התשע"ד in an article by Tamar Katz. Available online on jstor].