INDEFENSIBLE
indefensible, insupportable, unjustifiable, unwarrantable, unwarranted
(adjective) incapable of being justified or explained
indefensible, untenable
(adjective) (of theories etc) incapable of being defended or justified
indefensible
(adjective) not able to be protected against attack
Source: WordNet® 3.1
Etymology
Adjective
indefensible (comparative more indefensible, superlative most indefensible)
Not defensible; not capable of being defended
Synonym: vulnerable
Incapable of being justified or excused
Synonyms: inexcusable, unpardonable
Incapable of being explained
Synonyms: untenable, insupportable, invalid
Antonyms
• defensible
Source: Wiktionary
In`de*fen"si*ble, Etym: [Pref. in- not + defensible: cf. OF.
indefensible, indefensable.]
Definition: Not defensible; not capable of being defended, maintained,
vindicated, or justified; unjustifiable; untenable; as, an
indefensible fortress, position, cause, etc.
Men find that something can be said in favor of what, on the very
proposal, they thought utterly indefensible. Burke.
Source: Webster’s Unabridged Dictionary 1913 Edition