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accurate to a hair

accurate to a hair

8.1
So exact that it leaves no room for error
  • idiom
  • Informal
translation icon : exacto al milímetro
  • The engineer’s calculations were accurate to a hair, guaranteeing the machine would function flawlessly.

Examples

  • She measured the distance accurate to a hair, ensuring absolute precision in her experiment.

  • The scientist's measurements were accurate to a hair.

  • Every cut made by the jeweler was accurate to a hair to create a perfect gemstone.

  • Can you ensure that your calculations are accurate to a hair?

  • Every cut made by the jeweler was accurate to a hair to create a perfect gemstone.

  • The engineer’s calculations were accurate to a hair, guaranteeing the machine would function flawlessly.

  • She measured the distance accurate to a hair, ensuring absolute precision in her experiment.

Synonyms

exact
vsaccurate to a hair
901 3.2

Completely correct in every small detail

is used to stress absolutely no allowance for mistakes
accurate
vsaccurate to a hair
680 3.0

Exactly correct in every detail

is used with extra emphasis on absolute, errorless result
precise
vsaccurate to a hair
286 3.6

Exactly correct and clear about small details

is stronger, insisting on zero allowance for mistakes
true
vsaccurate to a hair
261 1.0

Exactly aimed and hitting the intended point

is stricter, emphasizing absolute lack of any error
spot on
vsaccurate to a hair
  • UK
42 4.4

Exactly right about a fact or idea

is more forceful about completely error-free measurement
on the money
vsaccurate to a hair
  • Informal
31 6.0

Exactly right in what someone says or does

is narrower, stressing flawless measurement rather than general rightness
on the nose
vsaccurate to a hair
  • Informal
15 5.9

Exactly correct in every detail

is more extreme, leaving literally no room for error
dead on
vsaccurate to a hair
6 4.8

Exactly correct about a fact or answer

is stricter, implying no allowable mistake at all
bang on
vsaccurate to a hair
  • UK
3 7.4

Exactly right for a situation or need

is more technical and strict about lacking any mistake
inch-perfect
vsaccurate to a hair
6.8

Very exact in size, position, or timing

is used to stress absolutely no margin for error

Antonyms

29 3.9

Nearly correct or exact but not completely

14 5.5

Not exact or clear enough to be useful

How Accurate

perfect
1.0
accurate to a hair
  • Informal
8.1
exact
901 3.2
accurate
680 3.0
approximate
29 3.9

Surface Forms

Morphology

accurate + to + a + hair

The phrase is compositionally built from 'accurate' (precise) plus the measure phrase 'to a hair', where 'hair' is commonly used metaphorically to mean a very small margin; the pattern 'accurate to X' (e.g. 'accurate to an inch') makes the degree-of-precision meaning predictable. This compositional and cross-linguistically common use of a small-object-as-measure makes the overall meaning inferable by a B1 learner who knows the constituents.

Etymology

Accurate to a hair may come from the picture of using one thin hair as the smallest measure; if something is right down to a hair, only a hair would show any difference. So, it means 'extremely precise' or 'very exact'.