Correct

忘年交

/ wàng nián jiāo / 
Strokes
https://i.cchatty2.com/filters:format(webp)/fit-in/684x0/img/202102/忘年交-Chinese-idioms-Cchatty-0cee3e15-c478-4900-bb25-e553ecd1390e-1612777071.jpg

Collocation

1
结为忘年交
2
成了忘年交

Definition

忘年交:

Literally means:

friendship between generations

Actually means:

It refers to friendship between different ages or generations.

指年龄或辈分不同的人之间结成的知心朋友。

Example

Used as object. (作宾语)
1
Tāmen
他们
yīlǎoyīshǎo
一老一少
  
,
suīrán
虽然
xiāngchà
相差
sānshí
三十
suì
岁
  
,
wàngniánjiāo
忘年交
  
。

They are old and young, though the difference is thirty years old, forget the new year.

2
Lǎoniánrén
老年人
hé
和
xiǎoqīngnián
小青年
bùdàn
不但
kěyǐ
可以
xiānghù
相互
gōutōng
沟通
  
,
érqiě
而且
yǒu
有
kěnéng
可能
jiēwéi
结为
wàngniánjiāo
忘年交
  
。

Older people and young people can not only communicate with each other, but also have the potential to forget the new year.

3
Shuō
说
shízài
实在
de
的
  
,
dāngchū
当初
wǒ
我
hái
还
rènwéi
认为
wáng
王
dàyé
大爷
yǒudiǎn
有点
bùhǎo
不好
jiējìn
接近
  
,
kěshì
可是
rìzi
日子
cháng
长
le
了
yǐhòu
以后
  
,
wǒmen
我们
jiù
就
mànmàn
慢慢
de
地
biànchéng
变成
le
了
wúsuǒbùtán
无所不谈
de
的
wàngniánjiāo
忘年交
le
了
  
。

To tell you the truth, at the beginning I thought that Master Wang was a little bad to approach, but after a long day, we slowly became an all-encompassing year-forgetting.