They bristled at his denigrating description of their activities.是什么意思？

They bristled at his denigrating description of their activities.

听到他在污蔑他们的活动, 他们都怒发冲冠。

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

bristled

adj. 有刚毛的，多刺毛的；

例句
He bristled with indignation at the suggestion that he was racist.
有人暗示他是个种族主义者，他对此十分恼火。

at

prep. （表示位置）在，在（某时间或时刻），以，达， 向，朝；n. 阿特（老挝辅币单位，100 阿特 = 1 基普）；

例句
Prices start at £13.95 a metre for printed cotton...
印花棉布以每米13.95英镑的价格起售。

his

pron. (he的所有格)他的，(he的物主代词)他的东西；det. 属于他的，用于名词前，自己的，指某人的，上帝的；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

denigrating

v. <正>诋毁，诽谤( denigrate的现在分词 )；

例句
They bristled at his denigrating description of their activities.
听到他在污蔑他们的活动, 他们都怒发冲冠。

description

n. 描述，形容，种类，类型；

例句
Police have stressed that this is the most accurate description of the killer to date...
警方强调这是迄今对凶手最精确的描述。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

activities

n. 活动( activity的名词复数 )，活力，活动力；

例句
He wanted to alert people to the activities of the group...
他想提醒人们小心该团体的活动。