1. heat lightning bright flashes of light near the horizon without thunder
  2. heartening cheerfully encouraging
  3. entertaining agreeably diverting or amusing
  4. threatening suggesting or expressive of evil, harm, or danger
  5. hardening the act of making something harder
  6. dead reckoning navigation without the aid of celestial observations
  7. heat-releasing occurring or formed with the liberation of heat
  8. unthreatening not unfriendly or threatening
  9. retraining training for a new occupation
  10. life-threatening causing fear or anxiety by threatening great harm
  11. pertinent being of striking appropriateness
  12. training activity leading to skilled behavior
  13. determining having the power or quality of deciding
  14. straining an intense or violent exertion
  15. entertainingly in an entertaining manner
  16. heightening reaching a higher intensity
  17. disheartening causing someone to lose spirit, morale, or hope
  18. returning tending to be turned back
  19. deadening the act of making something futile and useless
  20. draining having a debilitating effect