focal vs thematic

focal

adj
  • Belonging to, concerning, or located at a focus. 

  • Limited to a small area. 

noun
  • The individual who is the focus of a study or review, when the study or review is based on that individual's interactions with others. 

  • The central or most important element of something; a focal element. 

  • A sign or similar type of marketing material designed to draw attention to special deals. 

  • An object that is used to focus concentration when performing magic. 

  • A representative of a group or class of people within an organizational system. 

  • An exemplar of a concept. 

  • A major point of interest; an attraction. 

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. 

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