a word or a part of a word that has a grammatical purpose but often has little or no meaning

In the sentence "I tidied up the room", the adverb "up" is a particle. 在句子 I tidied up the room 中，副词 up 是个小品词。

an extremely small piece of something such as dust, dirt, or sand

Dust particles must have got into the motor. 发动机里一定是进灰了。

If feels as though particles of sand are scratching the surface of your eyes.

smoke particles

a very small amount of something

She wouldn't give me even the slightest particle of information about what she'd been doing. 对于她所做的事情，她一丁点消息都不会透露给我。