• (RP) IPA: /ɪˈfɪʃənt/
• (America, Canada) IPA: /ɪˈfɪʃənt/, /əˈfɪʃənt/

efficient

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

   An efficient process would automate all the routine work.

   Our cleaners are almost too efficient: they throw away anything left out on a desk.

2. expressing the proportion of consumed energy that was successfully used in a process; the ratio of useful output to total input

   The motor is only 20% efficient at that temperature.

3. causing effects, producing results; bringing into being; initiating change (rare except in philosophical and legal expression efficient cause = causative factor or agent)

   Ownership, maintenance, or use of the automobile need not be the direct and efficient cause of the injury sustained

   • 1614, Walter Ralegh [i.e., Walter Raleigh], The Historie of the World […], London: […] William Stansby for Walter Burre, […], →OCLC ↗, (please specify |book=1 to 5):

     It was well said of Plotinus, that the stars were significant, but not efficient.

4. (proscribed, old use) effective, efficacious
   • 1801, Robert Southey, “(please specify the page)”, in Thalaba the Destroyer, volume (please specify |volume=I or II), London: […] [F]or T[homas] N[orton] Longman and O[wen] Rees, […], by Biggs and Cottle, […], →OCLC ↗:

     Ye wake no more to anguish;‥ ye have borne
     The Chosen, the Destroyer!‥ soon his hand
     Shall strike the efficient blow;
     Soon shaking off your penal forms, shall ye,
     With songs of joy, amid the Eden groves,
     Hymn the Deliverer’s praise!

   • 1856, William Dexter Wilson, An Elementary Treatise on Logic:

     The Efficient Cause is that from which emanates the force that produces the Effect

• inefficient

• French: efficace
• German: effizient
• Italian: efficiente, performante
• Portuguese: eficiente
• Russian: эффекти́вный
• Spanish: eficiente, eficaz

• French: efficace
• Italian: efficiente
• Portuguese: eficaz

• Portuguese: eficaz
• Spanish: eficaz

efficient (plural efficients)

1. (obsolete) a cause; something that causes an effect
   • 1643, Thomas Browne, Religio Medici, I.14:

     Some are without efficient, as God; others without matter, as Angels […].

   • a. 1758, Jonathan Edwards, Dissertation on Liberty and Necessity:

     This implies, that something happens without a cause. If it should be said, that motive in this case is not the efficient of the action or doing — this is granted; but at the same time, for reasons already given, it is denied, that the man himself is the efficient cause of it.