cos vs cuz

cos

conj
  • because 

noun
  • A variety of lettuce with long, crisp leaves. 

  • A cousin, cuz. 

cuz

conj
  • because 

adv
  • because 

noun
  • cousin (usually as a term of address, but not necessarily towards one's cousin) 

How often have the words cos and cuz occurred in a corpus of books? (source: Google Ngram Viewer )