that cannot be harmed or defeated 不会受伤害的;打不败的;安全的 to be in an invulnerable position 立于不败之地 Parents may seem invulnerable to their children. 父母似乎对他们的孩子无懈可击。 - invulnerable to something
The submarine is invulnerable to attack while at sea. 潜艇在海上是不会受到攻击的。
Word Originlate 16th cent. (earlier than vulnerable): from Latin invulnerabilis, from in- ‘not’ + vulnerabilis (from vulnerare ‘to wound’, from vulnus ‘wound’).