at ease vs jittery

at ease

prep
  • Allowed to refrain from being in rigid formation. 

  • Free of anxiety; not stressed or tense. 

  • In a relaxed position with the feet apart rather than at attention. 

jittery

adj
  • Having jitter, or unwanted signal characteristics. 

  • nervy, jumpy, on edge 

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