Open to injury or Criticism :

Solution (By Examveda Team)

One word substitute is Vulnerable


Invincible : too powerful to be defeated or overcome.
Vulnerable: exposed to the possibility of being attacked or harmed, either physically or emotionally.
Naive: (of a person or action) showing a lack of experience, wisdom, or judgement.
Sensitive: quick to detect or respond to slight changes, signals, or influences.