relaxed vs unflappable

relaxed

adj
  • Free from tension or anxiety; at ease; leisurely. 

  • Without physical tension; in a state of equilibrium. 

  • Made more lenient; less strict; lax. 

  • Of a muscle: soft, not tensed. 

unflappable

adj
  • Remaining composed and level-headed at all times; impossible to fluster; not becoming frustrated or irritated easily. 

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