oneth vs uppermost

oneth

adj
  • Used at the end of algebraic expressions indicating ordinal position that end in 1, such as (k+1)ᵗʰ 

  • 'first', or other ordinal derivatives of 'one', such as hundred-and-oneth or minus-oneth 

noun
  • A fractional part of an integer ending in one 

  • An ordinal value that is represented by an expression ending in 1 such as the (n + 1)th. 

uppermost

adj
  • At or nearest the top of something. 

  • Highest in rank, importance, etc. 

adv
  • In the highest position. 

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