a cause; something that causes an effect
"The sudden rainstorm proved to be the efficient cause of the traffic jam on the highway."
In plain English: An efficient person is someone who gets things done quickly and without wasting time or effort.
"The most efficient way to finish the project was to hire an expert team rather than doing it ourselves."
Usage: The word efficient is almost exclusively used as an adjective to describe processes or systems, not as a noun. When referring to a cause, use the noun cause instead.
being effective without wasting time or effort or expense
"an efficient production manager"
"efficient engines save gas"
making good, thorough, or careful use of resources; not consuming extra. Especially, making good use of time or energy
"The new engine is highly efficient because it delivers maximum power while consuming minimal fuel."
In plain English: Efficient means doing something well without wasting time or energy.
"The new software update made my computer much more efficient at handling large files."
Usage: Use efficient to describe a person, machine, or process that achieves maximum productivity with minimum wasted effort or expense. It specifically implies getting the best results while using the least amount of time, energy, or materials necessary.
Efficient entered Middle English in the late 14th century as a loanword from Old French and Latin, originally meaning "making" or "productive." By 1787, its sense had shifted to describe someone who is skilled at accomplishing tasks with little waste.