indefensible

Something that's indefensible is inexcusable — there's no way to justify it. It's indefensible to take candy from a baby, or to give candy TO a baby, for that matter.

Indefensible behavior is just plain terrible, and it can't be explained away. It's indefensible, for example, or for one country to drop a bomb on innocent civilians in another country. Indefensible, "not able to be defended," comes from in-, "not," plus the Latin defendere and its sense of "allege in defense."

Definitions of indefensible
1

adj not able to be protected against attack

Synonyms:
vulnerable
susceptible to attack

adj incapable of being justified or explained

Synonyms:
insupportable, unjustifiable, unwarrantable, unwarranted
inexcusable
without excuse or justification

adj (of theories etc) incapable of being defended or justified

Synonyms:
untenable
unreasonable
not reasonable; not showing good judgment

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