noun
definition
A cause; something that causes an effect
adjective
definition
Making good, thorough, or careful use of resources; not consuming extra. Especially, making good use of time or energy
example
An efficient process would automate all the routine work.
definition
Expressing the proportion of consumed energy that was successfully used in a process; the ratio of useful output to total input
example
The motor is only 20% efficient at that temperature.
definition
Causing effects, producing results; bringing into being; initiating change (rare except in philosophical and legal expression efficient cause = causative factor or agent)
example
Ownership, maintenance, or use of the automobile need not be the direct and efficient cause of the injury sustained
definition
(old use) effective