discernible

Compared meaning: easy to notice or recognize (adjective).

比较义项：容易被察觉、清晰可辨的（形容词）。

• marked

  Marked is a fairly formal word for a striking, definite degree of change or quality, and typically appears right before abstract nouns like 'improvement', 'difference', or 'increase' rather than describing a person directly.

  marked是较为正式的词，形容变化或性质达到显著、确定的程度，通常直接修饰improvement（改善）、difference（差异）、increase（增加）等抽象名词，一般不直接用来描述人。

  There was a marked improvement in the patient's condition overnight.

  那位病人的病情一夜之间出现了显著好转。

• pronounced

  Pronounced emphasizes that a feature, trait or effect stands out strongly to the eye or ear (an accent, a limp, a stutter), and unlike marked, it is commonly used to describe people or their characteristics.

  pronounced强调某种特征、性质或效果在视觉或听觉上表现得十分突出（如口音、跛行、口吃），并且与marked不同，它常用来描述人或人的特点。

  His stutter becomes more pronounced when he's nervous.

  他一紧张，口吃就变得更明显了。

• noticeable

  Noticeable is the plain, general word for anything easy to notice, without indicating strong intensity or formal register; it fits almost any everyday situation.

  noticeable是普通、常用的词，泛指容易被注意到的事物，不表示程度特别强，也没有语体正式与否的区别，几乎适用于任何日常场合。

  There was a noticeable drop in temperature after sunset.

  日落后气温出现了明显的下降。

• discernible 本词

  Discernible focuses on whether something can be detected or perceived at all, often needing careful attention, rather than on how strong it is; it is common in negative phrases like 'no discernible reason' and does not imply a large change.

  discernible强调的是某事物能否被察觉或辨别出来，往往需要仔细留意，而不是强调程度的强弱；它常用于no discernible reason（没有可辨识的理由）这类否定表达中，并不暗示变化很大。

  No discernible reason was given for the sudden policy change.

  对于这项政策的突然改变，没有给出任何可辨识的理由。

All four mean easy to notice. Marked is formal, for a striking change, not marked as in a marked man. Pronounced describes a trait that stands out. Noticeable is the plain, general word. Discernible asks if something can be detected, as in no discernible reason.

这四个词都可译为“明显的”“显著的”，在“容易被察觉、清晰可辨”这一义项上很容易混淆，但语气和使用场合不同：marked和pronounced强调程度强、变化或特征十分确定，noticeable是最中性、最常用的说法，discernible侧重“能否被察觉”而非程度强弱，常见于no discernible…这样的否定表达中。这里不比较marked作“做了记号的”“被盯上的”（如a marked man）等其他义项。