ill-defined

IPA/ˌɪl dɪˈfaɪnd/
IPA/ˌɪl dɪˈfaɪnd/

ill-defined — 形容詞

1. not clearly described, explained, or understood; lacking a precise meaning or se

1.形容詞B2
釋義

不明確的

未清楚說明或界定的

not clearly described, explained, or understood; lacking a precise meaning or set of limits — for example, an ill-defined role at work, or an ill-defined concept in an academic paper.

例句

The responsibilities of Ana's new role were ill-defined, so she often did other teams' work.

Ana 的新職位職責範圍不明確，所以她經常做其他團隊的工作。

subject often a role, goal, or concept

Some contract terms were ill-defined, so Dr. Okafor asked a lawyer for help.

合約中有幾項條款定義不明確，所以 Okafor 醫師請了一位律師協助。

同義詞
  • vague

    more common in everyday English; 'ill-defined' is more formal

  • ambiguous

    suggests multiple possible interpretations; 'ill-defined' may simply lack any clear meaning

  • unclear

    broader and less formal than 'ill-defined'

  • imprecise

    focuses on lack of exactness rather than lack of clear boundaries

反義詞
  • well-defined

    direct opposite; describes something with clear limits or meaning

  • clear

    more general; describes something easy to understand or see

文法句型

be + ill-defined

remain + ill-defined

leave + object + ill-defined

用法筆記

Frequently used with abstract nouns such as role, goal, concept, boundary, vision, policy, or terms. Common in academic, business, and formal writing contexts, where it describes something that has not been thought through or agreed upon clearly enough.

常見錯誤

❌I feel ill-defined about my career.
✅My career goals are ill-defined.
💡'ill-defined' describes plans or concepts, not a person's feelings.
❌He gave an ill-defined explanation.
✅He gave a vague explanation.
💡'vague' is more natural than 'ill-defined' for describing speech or answers.

2. having edges, outlines, or borders that are not sharp enough to be seen distinct

2.形容詞C1
釋義

輪廓模糊的

邊界或輪廓不清楚的

having edges, outlines, or borders that are not sharp enough to be seen distinctly — for example, an ill-defined shape in a photograph, or an ill-defined shadow on a medical scan.

例句

In the evening light, the footpath's edges became ill-defined and hard to see.

在傍晚的光線中，小徑的邊緣變得模糊不清，難以辨認。

physical edges become ill-defined in poor light

The old map's borders were ill-defined, so the students could not agree on who owned the region.

舊地圖上的邊界畫得很不清楚，學生們無法判定誰擁有該區域。

同義詞
  • indistinct

    can describe both sight and sound; 'ill-defined' is primarily visual

  • blurred

    suggests a smeared or unfocused appearance; stronger than 'ill-defined'

  • fuzzy

    informal; describes a soft, unclear outline

反義詞
  • well-defined

    direct opposite; having a clear, sharp outline

  • sharp

    common in photography and visual descriptions

文法句型

be + ill-defined

become + ill-defined

look + ill-defined

用法筆記

Typically describes physical features with unclear outlines — edges, borders, shapes, shadows. Also common in medical writing, where an 'ill-defined mass' or 'ill-defined shadow' on an X-ray or CT scan suggests a finding whose shape is not sharply bounded.

常見錯誤

❌The sound was ill-defined.
✅The sound was indistinct.
💡'ill-defined' normally applies to visual boundaries, not sounds.