sororal vs uterine

sororal

adj

  • Of or pertaining to a sister. 

  • Related through someone's sister. 

uterine

adj

  • Of or pertaining to the uterus. 

  • Born of the same mother but of a different father. 

noun

  • A uterine sibling. 

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