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unreliable

unreliable

10 4.3
Not safe because it might fail or break
  • adjective
  • /ˌʌn.rɪˈlaɪ.ə.bəl/
translation icon : inestable
  • As a result, the power supply is unreliable, making blackouts and brownouts common.
  • unreliable system
  • unreliable power
  • unreliable power supplies

And so that early in McLaren's current existence, they were miserably unreliable cars.

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Examples

  • At the moment, our satellites are somewhat unreliable.

  • I would say that like our ferry route is like relatively unreliable because it's not a major route.

  • In the examples we looked at, there were several aspects making those systems unreliable.

    Academic text (2000)
  • It's slow, the interior is awful, it's unreliable and badly built.

  • Which they rarely did because the weather was so unreliable and Oliver was away so often.

    Fiction book (1995)
  • Online programs are not recommended for schools with unreliable or intermittent Internet access.

    Academic text (2007)
  • Unsustainable costs and unreliable quality are stimulating changes in healthcare policy and practice.

    Academic text (2013)
  • The engine was so unreliable the plane flew with its ram air turbine constantly deployed just as a precaution.

  • Historical sources, both oral and written, are considered unreliable and therefore ignored (Fortes 1949:1-2).

    Academic text (1998)
  • Many people avoid using that app because it is often unreliable when it comes to tracking fitness goals.

Synonyms

unpredictable
vsunreliable
163 4.4

Likely to change suddenly and hard to know in advance

adds that unpredictability also carries danger of collapse
unstable
vsunreliable
80 4.4

Not steady and likely to change, fail, or fall

stresses active danger and high risk of sudden collapse
shaky
vsunreliable
53 3.3

Not firm or safe and likely to fail

emphasizes immediate dangerous collapse rather than general insecurity
treacherous
vsunreliable
38 7.1

Unstable ground, water, or weather that can suddenly become dangerous

is more general about being unsafe rather than only causing harm
faulty
vsunreliable
36 3.5

Not correct because it has mistakes, for example in an argument or plan

focuses on hazardous instability and high collapse risk rather than errors
insecure
vsunreliable
23 3.5

Not safe and likely to be damaged, like a building or job

highlights immediate collapse risk and dangerous instability
untrustworthy
vsunreliable
21 4.8

Not honest or reliable with promises

focuses more on dangerous instability and sudden collapse risk
dodgy
vsunreliable
  • UK
13 8.2

Likely to be unsafe or untrustworthy

is stronger, warning of likely unstable collapse rather than mere risk
flaky
vsunreliable
  • Informal
6 7.0

Tending to fail or change without warning

is more serious, stressing real danger and likely collapse
undependable
vsunreliable
3 4.7

Likely to fail or disappoint people

signals actual physical or sudden failure risk beyond mere unreliability
fly-by-night
vsunreliable
  • Offensive
2 8.9

Not reliable and likely to disappear quickly, often for dishonest reasons

conveys dangerous unpredictability and risk of sudden collapse
error-prone
vsunreliable
2 5.1

Tends to make many mistakes

points to physical or safety failure risk beyond simple error tendency
buggy
vsunreliable
1 3.9

Having many small errors or problems in a program

emphasizes dangerous instability and likely catastrophic failure risk
labile
vsunreliable
1 9.7

Able to change or break down easily

focuses more on risk of sudden dangerous failure
untrusted
vsunreliable
1 5.0

People do not see it as safe or reliable

adds the idea of actual dangerous failure rather than only distrust
unsturdy
vsunreliable
4.8

Likely to wobble or break, like a weak chair

covers broader unsafe failure risk beyond just weak build

Antonyms

473 2.3

Not likely to change and stays steady over time

358 2.7

Able to be trusted to do what is expected

How Reliable

inconsistent
96 4.7
undependable
3 4.7
untrustworthy
21 4.8
unreliable
10 4.3

Surface Forms

unreliable positive
unreliabler comparative
unreliablest superlative

Morphology

unreliable = reliable (transparent) = un + rely + able

The negative prefix 'un-' applied to 'reliable' yields the expected opposite meaning; the sense of 'not safe or dependable' falls within normal uses of this negation.

Etymology

Unreliable is made of the parts un- meaning 'not', rely meaning 'depend on', and -able meaning 'can be'. When we call a machine, road, or bridge unreliable, we mean it 'cannot be depended on' and so it may fail or be unsafe to use.