He is a party to the case or a near relative of a party;

是本案的当事人或者当事人的近亲属；

youdao

Despite all the hoopla, Palo Alto's 100th birthday party is actually designed to be a simple, down-to-earth affair.

除了喧闹外，帕罗奥图一百岁生日聚会实际上被设计为一个简朴实惠的活动。

《柯林斯英汉双解大词典》

The transition from a dictatorship to a multi-party democracy is proving to be difficult.

从专政国家到多党民主国家的转型证明是很艰难的。

《柯林斯英汉双解大词典》

Sometimes I feel like a fish out of water when I go to a party and everyone but me is doing the latest dance.

VOA: special.2011.04.10

Hollywood is the best if you want to come, have a good time, party,

你要想来好好玩，聚会，好莱坞再好不过了。

好莱坞是什么样的？ - SpeakingMax英语口语达人

You could use the "Is there" pattern to find out about whether there's a party and hopefully, you can receive an invitation.

你可以用“Is there”句型来确认是否有这样一个派对，希望自己能够得到邀请。

Is there 课堂 - SpeakingMax英语口语达人

Brazil is a party to the Nuclear Non-Proliferation Treaty since 1998 as a non-nuclear weapons state.

FORBES: Brazil's Senate OKs Tax Breaks for Nuclear Power

Every country with a shore in the region is a party to at least one territorial dispute.

FORBES: A new Japanese government could strain ties with America.

In other words, what Iran has disclosed under the Nonproliferation Agreement that Iran is a party to, those are it.

NPR: Article Claims CIA Has No Evidence of Iran Nuke Program