unsound

/ˌʌnˈsaʊnd/ (bre, ipa) · [ənsˈaʊnd] /ˌʌnˈsaʊnd/ (ame, ipa) · [ənsˈaʊnd] /ˌən-ˈsau̇nd How to pronounce unsound (audio)/ (ame, mw)

unsound — adjective

  • unsoundpositive
  • more unsoundcomparative
  • most unsoundsuperlative

1. describes advice, reasoning, evidence, or decisions that are so weak, mistaken,

1.形容詞C1
釋義

describes advice, reasoning, evidence, or decisions that are so weak, mistaken, or poorly supported that they should not be accepted or trusted.

例句

Élise rejected the report because its central claim rested on unsound evidence.

collocation: unsound evidence

Jiwoo warned that the board's unsound budget would leave the clinic in debt.

finance: unsound budget

同義詞
  • flawed

    emphasises a defect inside the reasoning or plan itself

  • invalid

    more formal and common for arguments, laws, or conclusions that fail a rule-based test

  • unreliable

    broader; often used when the evidence or advice cannot be trusted consistently

反義詞
  • sound

    direct opposite for reasoning, advice, or evidence that can be trusted

  • well-founded

    emphasises that the view rests on solid evidence or reasons

用法筆記

Most common in formal discussion of arguments, verdicts, advice, and financial plans. Distinguish from sense 2: this sense is about weak support or poor judgment, not physical weakness in an object.

常見錯誤

The idea is unsoundly.
The idea is unsound.
💡Use the adjective after be, not the adverb.

2. describes a building, floor, wall, or other structure whose parts have weakened

2.形容詞C1
釋義

describes a building, floor, wall, or other structure whose parts have weakened so much that it may break, sink, or fall.

例句

Christopher stepped away when the inspector said the balcony was unsound.

structure judged unsafe to trust

Salt water had made the old pier unsound near its wooden posts.

cause: water damage weakens structure

同義詞
  • unstable

    focuses on poor support or balance rather than overall condition

  • unsafe

    broader; can describe any danger, while unsound points to physical weakness in the structure

  • rickety

    more informal and suggests visible wobbling or looseness

反義詞
  • sound

    direct opposite for structures in good physical condition

  • solid

    emphasises firm construction and strength

用法筆記

Usually used in inspections, repair reports, and safety warnings. It often follows be, become, or declare when someone judges a structure too weak to trust.

常見錯誤

My phone is unsound after I dropped it.
My phone is faulty after I dropped it.
💡Use this sense for buildings or structures, not ordinary devices.

3. describes someone whose mind is affected by serious mental illness, so they cann

3.形容詞C1
釋義

describes someone whose mind is affected by serious mental illness, so they cannot think or judge in a normal way.

例句

The court found Sade mentally unsound and delayed the sentencing hearing.

formal phrase: mentally unsound

Nellie feared her uncle was becoming unsound after he began hearing voices at night.

pattern: become unsound

同義詞
  • mentally ill

    plain descriptive term, less legal in tone

  • insane

    stronger and often used in legal or dramatic contexts

  • deranged

    more old-fashioned and strongly negative

反義詞
  • sane

    able to think and judge normally

  • sound of mind

    formal opposite in legal and medical contexts

用法筆記

Often appears in legal or medical writing, especially in the phrase 'of unsound mind'. Distinguish from sense 4: this sense concerns mental judgment, not bodily illness or injured organs.

常見錯誤

The printer is unsound.
The printer is faulty.
💡Use this sense for a person's mental condition, not for broken machines.

4. describes a body, organ, or animal that is diseased or not functioning in a heal

4.形容詞C1
釋義

describes a body, organ, or animal that is diseased or not functioning in a healthy way.

例句

The vet said the horse was unsound in one front leg.

pattern: unsound in one leg

After the infection spread, Amelia's left lung became unsound.

medical use for an organ

同義詞
  • diseased

    more medical and explicit about illness

  • ailing

    broader and often used for people rather than organs

  • unhealthy

    broader; can describe habits or environments as well as bodies

反義詞
  • healthy

    direct opposite for a body, animal, or organ in good condition

  • sound

    formal opposite, especially for body parts and animals

用法筆記

Most common with body parts, teeth, feet, and animals in veterinary or older medical writing. Distinguish from sense 2: this sense refers to disease or bodily weakness, not damaged buildings or materials.

常見錯誤

The plan is unsound in one leg.
The horse is unsound in one leg.
💡The pattern 'unsound in ...' belongs to physical health, usually of an animal or body part.