inefficient

Etymology

It is formed from English in- + efficient, with the negative prefix in-.^{[2][3][4][5][6]} Efficient is from Old French efficient and efficiēns, the present participle of efficiō (“to work out, accomplish”),^[2][3] from ex (“out”) and faciō (“to make, do”).^[2]

Earliest recorded meaning

Of a person, not accomplishing what one has to do, lacking the ability or industry required: 1750, in a letter of Lord Chesterfield,^[2][3][5] who also used inefficiency in 1749.^[3] Etymonline dates the adjective to 1748, in the sense "not producing the desired effect".^[4]

Semantic evolution

In 1750 efficient itself still meant above all "causing, producing", as in efficient cause; the OED dates its sense "productive of effects; adequately skilled" only from 1787.^[2] Inefficient was used of people from the start;^[2] it is now also used of systems and methods that waste time or energy.^[5][7] The noun, an inefficient person, is recorded from 1898, in the Times.^[2][6]

Timeline

• 1748 – not producing the desired effect, according to Etymonline.^[4]
• 1750 – of a person, not capable of what is required.^[2][3]
• 1898 – noun, an inefficient person.^[2]

Meanings

Adjective

1. Not working well, or wasting time, energy or money: an inefficient heating system.^[7][5]
2. Of a person, lacking the skill or ability to do a task well; incompetent.^[7][2][6]
3. Not producing the result wanted; inefficacious.^[7][5]

Noun

1. An inefficient person.^[5][2][6]

Word family

• inefficiently

Related words

• efficient
• inefficiency
• efficacious
• inefficacious
• effect

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
7. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins