Indefensible
Part of speech: adjective
Definition: Not defensible; not capable of being defended; vulnerable. Incapable of being justified or excused; inexcusable; unpardonable. Incapable of being explained; untenable; insupportable; invalid.
Example sentence: My personal opinion is that life begins at the point of conception, and abortion is morally indefensible.
Unreasonable
Part of speech: adjective
Definition: not reasonable
Example sentence: There is no such thing as an unreasonable question, or a silly question, or a frivolous question, or a waste-of-time question. It's your life, and you've got to get these answers.