Adjective

(en adjective)

Making good, thorough, or careful use of resources; not consuming extra. Especially, making good use of time or energy.

* {{quote-magazine, title=A better waterworks, date=2013-06-01, volume=407, issue=8838

, page=5 (Technology Quarterly), magazine=(The Economist) citation , passage=An artificial kidney these days still means a refrigerator-sized dialysis machine. Such devices mimic

Using a particular proportion of available energy.

Causing effects; producing results.

* Wilson

The efficient cause is the working cause.

Adjective

(en-adj)

Suitable; appropriate; fit or fitted; suited.

Tonight there’s a full moon, which is apt , since the election night will bring out the lunatics.

* (Jeremy Taylor) (1613–1677)

a river apt to be forded by a lamb

(of persons or things) Having a habitual tendency; habitually liable or likely; disposed towards.

* (1628–1699)

My vines and peacheswere apt to have a soot or smuttiness upon their leaves and fruit.

* (1834-1913)

This tree, if unprotected, is apt to be stripped of its leaves by a leaf-cutting ant.

* (Fairfax Harrison) (1869-1938)

that lofty pity with which prosperous folk are apt to remember their grandfathers

Ready]]; especially fitted or [[qualify, qualified (to do something); quick to learn; prompt; expert; as, a pupil apt to learn; an apt scholar.

* (rfdate) Johnson

An apt wit.

* (rfdate) (William Shakespeare) (1564-1616)

*:(Although I) live a thousand years, I shall not find myself so apt to die.