Adjective

(en adjective)

Helpful or good to something or someone.

* {{quote-magazine, date=2013-06-29, volume=407, issue=8842, page=72-3, magazine=(The Economist)

, title= A punch in the gut , passage=Mostly, the microbiome is beneficial . It helps with digestion and enables people to extract a lot more calories from their food than would otherwise be possible. Research over the past few years, however, has implicated it in diseases from atherosclerosis to asthma to autism.}}

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.