attendant vs synergistical

attendant

adj
  • Going with; associated; concomitant. 

  • Depending on, or owing duty or service to. 

noun
  • One who attends; one who works with or watches over something. 

  • That which accompanies or follows. 

  • A servant or valet. 

  • One who owes a duty or service to another. 

synergistical

adj
  • Synonym of synergistic 

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