What is the difference between Abate and Abet?

What is the difference between Abate and Abet? : 
Abate : 

( 1 ) Become less

I left home when the storm had abated. 

( 2 ) Make less

People are campaigning to abate the noise in the cities. 
Abet : 

( 1 ) Help or encourage somebody to commit an offence or do something wrong

He was abetted in these illegal activities by his wife. 

( 2 ) Encourage a crime

You are abetting theft.