arrow-finger vs thumby

arrow-finger

noun

  • the forefinger 

thumby

noun

  • A little thumb; diminutive term for thumb 

adj

  • Clumsy, awkward, maladroit, not dextrous, all thumbs 

  • Dirtied by thumb marks 

How often have the words arrow-finger and thumby occurred in a corpus of books? (source: Google Ngram Viewer )