blackening vs welt

blackening

noun
  • The result or an instance of such an act or process; a black stain or mark. 

  • The act or process of turning (becoming) black in colour. 

  • Any of various (dark-colored) surface treatments for metal substrates, to inhibit corrosion; on steel, generally, synonym of bluing. 

  • The act of defaming or sullying. 

welt

noun
  • A ridge or lump on the skin, as caused by a blow. 

  • A strip of leather set into the seam between the outsole of a shoe and the upper, through which these parts are joined by stitching or stapling. 

  • In steam boilers and sheet-iron work, a strip riveted upon the edges of plates that form a butt joint. 

  • In carpentry, a strip of wood fastened over a flush seam or joint, or an angle, to strengthen it. 

  • In machine-made stockings, a strip, or flap, of which the heel is formed. 

  • A narrow border, as of an ordinary, but not extending around the ends. 

  • A feature resembling a welt. 

  • A strip of material or covered cord applied to a seam or garment edge to strengthen or cover it. 

verb
  • To cause to have welts; to beat. 

  • To install welt (a welt or welts) to reinforce. 

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