riddle vs ruddle

riddle

verb
  • To put something through a riddle or sieve; to sieve; to sift. 

  • To fill with holes like a riddle. 

  • To speak ambiguously or enigmatically. 

  • To fill or spread throughout; to pervade. 

  • To solve, answer, or explicate a riddle or question. 

noun
  • A board with a row of pins, set zigzag, between which wire is drawn to straighten it. 

  • A verbal puzzle, mystery, or other problem of an intellectual nature. 

  • A sieve with coarse meshes, usually of wire, for separating coarser materials from finer, as chaff from grain, cinders from ashes, or gravel from sand. 

  • An ancient verbal, poetic, or literary form, in which, rather than a rhyme scheme, there are parallel opposing expressions with a hidden meaning. 

  • One of the pair of curtains enclosing an altar on the north and south. 

ruddle

verb
  • To sift together; to mix, as through a sieve. 

  • To mark something with red ochre. 

  • To raddle or twist. 

noun
  • A form of red ochre sometimes used to mark sheep. 

  • A riddle or sieve. 

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