BORING 乏味的, not interesting or exciting

无趣的，枯燥的，沉闷的，无聊的:

Life is never dull when Elizabeth is here.

伊丽莎白在这里生活就决不会无聊了。

a dull movie

一部沉闷的电影

It sounded pretty dull to me.

在我听来，这很无聊。

The weekly meeting tends to be deadly dull (=very dull) .

每周一次的会议总是十分无聊。

Last week we had a hurricane. Never a dull moment running a hotel in the Caribbean (=it's always interesting or exciting) .

上周我们这里刮飓风了，在加勒比海开旅馆从来都很刺激。

COLOUR / LIGHT 颜色/光, not bright or shiny

暗淡的，不鲜明的:

The bird is dull brown and gray in colour.

这鸟是暗淡的棕灰色。

Her eyes were dull with dark shadows beneath them.

她的眼睛暗淡无光，底下有黑眼圈。

the dull afternoon light

暗淡的午后光线

WEATHER 天气, not bright and with lots of clouds

阴沉的，昏暗的:

Outside the weather was hazy and dull.

外面薄雾朦胧，天色灰暗。

a dull sky

阴沉的天空

PAIN 疼痛, a dull pain is not severe but does not stop

隐约的，轻微而持续的;

a dull ache in her lower back

她背下方的隐痛

The pain was dull but persistent.

痛感不严重但一直未消。

SOUND 声音, not clear or loud

不清楚的，沉闷的:

The gates shut with a dull thud .

随着一声闷响，大门关上了。

KNIFE / BLADE 刀/刃, not sharp

不锋利的，钝的;

NOT INTELLIGENT 不聪明的, [old-fashioned] not able to think quickly or understand things easily

愚笨的，迟钝的;

If you don't understand then you're duller than I thought.

如果你不明白的话，那么你就比我原先想的还要笨。

TRADE 交易, if business on the Stock Exchange is dull, few people are buying and selling

〔股市〕清淡的，交易不畅的

'Well Michael?' he said dully.

“怎么样，迈克尔？”他木然地说。

Her stomach ached dully.

她的胃隐隐作痛。

[T] to make something become less sharp or clear

使麻木，使迟钝:

He drank some alcohol to dull the pain .

他喝了些酒来减轻疼痛。

Her fear and anxiety dulled her mind.

恐惧和焦虑使她迷迷糊糊的。

[I,T] to become less bright or loud, or to make something become less bright or loud

（使）变得暗淡，（使）变低沉:

His eyes dulled a little.

他的眼神变得暗淡了一些。

The constant rain dulled all sound.

连续不断的雨使得所有的声音都变低沉了。