Main entry: impossible
Definition: not capable of occurring or being accomplished or dealt with
Usage: an impossible dream; an impossible situation
Antonyms: possible
Definition: capable of happening or existing
Antonyms: safe
Definition: having reached a base without being put out
Antonyms: hopeful
Definition: having or manifesting hope
Main entry: out of the question, impossible, inconceivable, unimaginable
Definition: totally unlikely
Antonyms: thinkable
Definition: capable of being conceived or imagined or considered
Main entry: unacceptable, insufferable, impossible, unsufferable
Definition: used of persons or their behavior
Usage: impossible behavior; insufferable insolence
Antonyms: tolerable
Definition: capable of being borne or endured