invincibly       
adverb uk/ɪnˈvɪn.sə.bli/ us/ɪnˈvɪn.sə.bli/
 不可战胜地;不可阻挠地
in a way that is impossible to defeat or prevent from doing what is intended
  I remain invincibly confident that Mr Shaw will win the election. 我仍然坚信肖先生将赢得选举。 
 The soldiers marched invincibly shoulder to shoulder toward their enemy. 士兵们并肩向敌人前进,所向披靡。 
 See: invincible
 - More examples
 - His manner and remarks seem invincibly calm and upbeat.
 - "I'll be fine!" she said invincibly.
 - Only someone who was invincibly hard-hearted would not be moved by this sight.