From Longman Dictionary of Contemporary Englishunassailableun‧as‧sail‧able /ˌʌnəˈseɪləbəl◂/ adjective formal EFFECTIVEnot able to be criticized, made weaker, or beaten an unassailable argument The party’s position looked unassailable. The result gave the team an unassailable lead.
Examples from the Corpus
unassailable• Its editorial integrity ought to be unassailable, at least in its hard news sections.• You are too used to dealing with theists who adopt a position of unassailable certainty in their beliefs.• But part of him, something of his character that had been forbearing and unassailable, had let him down.• The result gives Walsall Kipping an unassailable lead with one round of matches left.• unassailable logic• He offers the unassailable proposition that without money there can be no inflation.• For the girls it is an unassailable tradition.• Most of the students felt that sincerity was an unassailable virtue: what mattered was to say what you felt.position ... unassailable• You are too used to dealing with theists who adopt a position of unassailable certainty in their beliefs.