flitch vs tranche

flitch

verb
  • To cut into, or off in, flitches or strips. 

noun
  • The flank or side of an animal, now almost exclusively a pig when cured and salted; a side of bacon. 

  • A piece or strip cut off of something else, generally a piece of wood (timber). 

tranche

verb
  • To divide into tranches. 

noun
  • A distinct subdivision of a single policyholder's benefits, typically relating to separate premium increments. 

  • One of a set of classes or risk maturities that compose a multiple-class security, such as a CMO or REMIC; a class of bonds. Collateralized mortgage obligations are structured with several tranches of bonds that have various maturities. 

  • A pension scheme's or scheme member's benefits relating to distinct accrual periods with different rules. 

  • A slice, section or portion. 

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