Common Meanings
1
dòng洞
a hole, cave, or cavity
这个山洞很深，里面可能住着小动物。
This mountain cave is very deep; small animals might live inside.
To make a hole in; to bore through; to penetrate.
子弹洞穿了木板。
The bullet bored through the wooden plank.
Thoroughly; clearly; to penetrate or perceive deeply.
他善于洞察人心，总能理解别人的真实想法。
He is good at discerning people's hearts and can always understand others' true thoughts.
Used orally to represent the digit zero (零, líng) in sequences of numbers, such as phone numbers or room numbers, especially to avoid confusion with other sounds.
我的电话号码是三五洞八七九一。
My phone number is three five 'dòng' eight seven nine one.