apprehension vs qualm

apprehension

noun
  • Anticipation, especially of unfavorable things such as dread or fear or the prospect of something unpleasant in the future. 

  • Opinion; conception; sentiment; idea. 

  • The faculty by which ideas are conceived or by which perceptions are grasped; understanding. 

  • The physical act of seizing or taking hold of (something); seizing. 

  • Perception; the act of understanding using one's intellect without affirming, denying, or passing any judgment 

  • The act of seizing or taking by legal process; arrest. 

qualm

noun
  • A feeling of apprehension, doubt, fear etc. 

  • A prick of the conscience; a moral scruple, a pang of guilt. 

  • A sudden sickly feeling; queasiness. 

verb
  • To have a sickly feeling. 

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