Sufficient
Part of speech: adjective
Definition: Equal to the end proposed; adequate to wants; enough; ample; competent; as, provision sufficient for the family; an army sufficient to defend the country. Possessing adequate talents or accomplishments; of competent power or ability; qualified; fit. Capable of meeting obligations; responsible. Self-sufficient; self-satisfied; content.
Part of speech: determiner
Definition: the smallest amount needed
Efficient
Part of speech: adjective
Definition: Making good, thorough, or careful use of resources; not consuming extra. Especially, making good use of time or energy.Using a particular proportion of available energy.