Adjective

(en adjective)

Powerful, mighty, having authority.

* 1599 — Shakespeare, Hen V i 2

Awake remembrance of these valiant dead, / And with your puissant arm renew their feats.

* 1667 — Book I

For who can yet believe, though after loss,
That all these puissant legions, whose exile
Hath emptied Heaven, shall fail to re-ascend,
Self-raised, and repossess their native seat?

*

I cried in a loud voice, "Long live the most puissant king of Lilliput!"

* 1851 ,

How comes all this, if there be not something puissant in whaling?

* 1961 -

In fact the titles could be anything-or (with some of the most puissant ) no title at all...

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.