坚定的英文：
firm
steady
staunch

参考例句：

He's a staunch supporter of the monarchy.
他是君主制的坚定拥护者。

They are staunch supporters of the Republican Party.
他们是共和党的坚定支持者。

Steadfastness,as in purpose or affection;faithfulness.
坚定(目标或感情上的)坚定不移;忠诚

Eleanor was brusque and firm and businesslike.
埃莉诺态度粗暴，意志坚定、办事认真。

Not discouraged or disheartened;resolutely courageous.
无畏的不泄气的，不气馁的；坚定而勇敢的。

His dapper self-confidence seemed impenetrable to such hints
这类的暗示似乎动摇不了他坚定的自信。

His dapper self-confidence seemed impenetrable to such hints.
这类的暗示似乎动摇不了他坚定的自信。

Our love grows stronger with every passing year. Happy Valentine's Day, Baby.
我俩的爱，一年比一年更坚定。小宝贝，情人节快乐。

She repeated the line over and over again in a dreamy but resolute and very audible voice
她以温柔而坚定的、清晰无误使人们能听得见的声音，把这句诗一遍又一遍地朗诵。

Born in America, Dawna Walter is a fast talker, a self-confessed perfectionist, and a tidiness fundamentalist.
多娜·沃尔特生于美国，说起话来滔滔不绝，自称是一个完美主义者，也是一位坚定的信奉整洁的人。

firm是什么意思：
n. 商号；企业
adj. 坚定的；坚固的；强有力的；确定的；坚挺的；严格的
v. （使）坚固；变坚实；加强；使坚定；回升
adv. 坚定地

Are the firm's finances sound?
这家公司的财务状况可靠吗?

His step was not as sharp and firm.
他的脚步不再像从前那样敏捷、坚实。

To become firm or gelatinous; congeal.
凝固凝结或变硬；冻结

steady是什么意思：
adj. 稳定的，不变的；镇定的
v. 恢复平稳；使稳定，使坚定

The boat soon steadied again.
那船很快又稳定了下来。

Danger steadies some people.
有的人在危险时候反而坚定。

The flow of fluid is steady.
液体的流动很稳定。

staunch是什么意思：
adj. 坚固的；坚定的，忠诚的
v. 止住；止血

He is a staunch communist.
他是个坚定的共产主义者。

Sophia staunched the blood with a cloth.
索菲亚用一布块止住了血。

The Party has made him a staunch communist. [The Party has made a staunch communist of him.]
党把他培养成坚强的共产主义战士。