apprehend vs pick up

apprehend

verb
  • To seize or take (a person) by legal process; to arrest. 

  • To be or become aware of (something); to perceive. 

  • To have a conception of (something); to consider, to regard. 

  • To seize or take (something); to take hold of. 

  • To understand. 

  • To be of opinion, believe, or think; to suppose. 

  • To be apprehensive; to fear. 

  • To anticipate (something, usually unpleasant); especially, to anticipate (something) with anxiety, dread, or fear; to dread, to fear. 

  • To acknowledge the existence of (something); to recognize. 

  • To take hold of (something) with understanding; to conceive (something) in the mind; to become cognizant of; to understand. 

pick up

verb
  • To collect and detain (a suspect). 

  • To acquire (something) accidentally; to catch (a disease). 

  • To lift; to grasp and raise. 

  • To clean up; to return to an organized state. 

  • To point out the behaviour, habits, or actions of (a person) in a critical manner; used with on. 

  • To meet and seduce somebody for romantic purposes, especially in a social situation. 

  • To receive calls; to function correctly. 

  • To record; to notch up. 

  • To learn, to grasp; to begin to understand; to realize. 

  • To promote somebody who was previously passed over. 

  • To collect an object, especially in passing. 

  • To answer a telephone. 

  • To take control (physically) of something. 

  • To mark, to defend against an opposition player by following them closely. 

  • To behave in a manner that results in a foul. 

  • To restart or resume. 

  • To receive (a radio signal or the like). 

  • To notice, detect or discern; to pick up on 

  • To improve, increase, or speed up. 

  • To reduce the despondency of. 

  • To pay for. 

  • To obtain and publish a story, news item, etc. 

  • To collect a passenger. 

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