sidelong vs sneaking

sidelong

adj
  • Indirect; suggestive; not straightforward. 

  • Slanting or sloping; oblique. 

  • Directed to the side; sideways. 

  • Along the side of something. 

adv
  • obliquely 

  • Towards the side; sideways. 

sneaking

adj
  • Secret or underhand; not openly avowed. 

noun
  • The act of one who sneaks. 

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