invulnerable

a.刀枪不入的，攻不破的

invisibly, invitation, invite, invite sb. to (sth.,a place), inviting, invitingly, invocation, invoice, invoke, involuntarily, involuntariness, involuntary, involute, involuted, involution, involve, involved, involvement, involvement in, invulnerability, inward, inward (also inwards), inward(s), inwardly, inwardness, inwards, iodine, iodize, iodise, IOM, ion, Ionic, ionization, ionisation, ionize, ionise, ionosphere, iota, IOU, IOW, Iowa, IPA, ipso facto,