ETYM Latin futilis that easily pours out, that easily lets loose, vain, worthless, from the root of fundere to pour out: cf. French futile. Related to Fuse.
Producing no result or effect; SYN. ineffectual, otiose, unavailing.

ETYM French from Latin impossibilis; pref. im- not + possibilis possible. Related to Possible.
1. Not capable of occurring or being accomplished or dealt with.
2. Totally unlikely; SYN. inconceivable out of the question unimaginable.
3. Used of persons or their behavior; SYN. insufferable unacceptable unsufferable.

ETYM Pref. in- not + conceivable: cf. French inconcevable.
Not conceivable; incapable of being conceived by the mind; not explicable by the human intellect.

ETYM Latin praeposterus; prae before + posterus coming after, latter. Related to Posterior.
Contrary to nature or reason; utterly and glaringly foolish; unreasonably absurd; perverted.