epithalamic vs spousal

epithalamic

adj
  • Of or pertaining to the epithalamus. 

  • Belonging to, or designed for, an epithalamium. 

spousal

adj
  • of or relating to a spouse, spouses; to the relationship between spouses 

  • of or relating to marriage 

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