年纪大的英文：
long in the tooth

参考例句：

Exhausted though he was, he was not ashamed to learn.
他虽然年纪大了，但不耻于学习。

You're only young once(saying)(because they will have plenty to worry about when they get older)
(谚)应准予年轻人及时行乐(因为年纪大时要有很多操心事).

He didn't let the older boys buffalo him.
他没让比他年纪大的男孩唬住。

He's getting deafer in his old age.
他年纪大了耳朵越来越聋.

The elder of the two brothers
两兄弟中年纪大的一个

The game will lose its relish when you grow old.
你年纪大了以后，这种娱乐就会变得没意思了。

As one advances in years, it is prudent to haul in one's horns more and more as to physical activity
一个人年纪大了，逐渐减少体力活动是明智的。

If you are young, I will be your comrade; if you are old, I will be your son.
假如你年轻，我就做你的伙伴；假如你年纪大了，我就做你的儿子。

Don't set him the task. For one thing he's old; for another he's in poor health.
不能让他去干， 一则年纪大，二则身体弱。

When dealing with teachers, bosses, someone who is older, seniors, one should never call them by their names.
一个人对老师、上司﹐对比自己年纪大、资格老的人﹐绝对不能直呼其名。

long是什么意思：
adj. 长的；长时间的；冗长的；长音的
adv. 长久地，长期地；始终
n. 长时间，长时期；长音节
v. 渴望
abbr. 经度，经线

But perhaps not for long.
但这并不会持续太长时间。

It will take a long time to read through this long story.
要读完这长篇故事要花相当长的时间。

propagation of long and very long wave in the ionosphere
电离层长波和超长波传播

The article is too long, it has to be cut.
这篇文章太长了，要删减。

This stuff wears long.
这种料子很经穿。

tooth是什么意思：
n. 牙齿，齿状物
v. 给…装齿；啮合

An eye for an eye and a tooth for a tooth
以眼还眼,以牙还牙

The hole in the tooth is cavity.
牙上的洞叫做蛀牙。

contact depth of tooth
接触齿高|总啮合高度

She has a supernumerary tooth.
她有一颗多生牙。

The stump of a pencil,cigar,tooth
铅笔头、雪茄烟蒂、牙的残根.