thematic vs valid

thematic

adj
  • Relating to, or having a theme (“subject”) or a topic. 

  • Relating to a melodic subject. 

  • Of or relating to a theme (“subdivision of the Byzantine empire”). 

  • Of a word stem, ending in a vowel that appears in or otherwise influences the noun or verb's inflection. 

noun
  • A postage stamp that is part of a thematic collection. 

valid

adj
  • Related to the current topic, or presented within context, relevant. 

  • Well grounded or justifiable, pertinent. 

  • Of an argument: whose conclusion is always true whenever its premises are true. 

  • Genuine - as distinguished from efficient or regular - sacrament. 

  • Of a formula or system: such that it evaluates to true regardless of the input values. 

  • Acceptable, proper or correct; in accordance with the rules. 

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