Main entry: demanding
Definition: requiring more than usually expected or thought due; especially great patience and effort and skill
Usage: found the job very demanding; a baby can be so demanding
Antonyms: undemanding
Definition: requiring little if any patience or effort or skill
Antonyms: leaky
Definition: permitting the unwanted passage of fluids or gases
Antonyms: loose
Definition: not tight; not closely constrained or constricted or constricting