unlink vs weld

unlink

noun
  • A link that is equivalent (under ambient isotopy) to finitely many disjoint circles in the plane. 

verb
  • To decouple; to remove a link from, or separate the links of. 

  • To delete (a file). 

weld

verb
  • To join two materials (especially two metals) together by applying heat, pressure and filler, either separately or in any combination. 

  • To bind together inseparably; to unite closely or intimately. 

noun
  • The joint made by welding. 

  • A herb (Reseda luteola) related to mignonette, growing in Europe, and to some extent in America, used to make a yellow dye. 

  • The yellow coloring matter or dye extracted from this plant. 

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