hairline

发际线、发线

He noticed his hairline had started to recede in his thirties.

他发现自己三十几岁时发际线就开始后退了。

细缝、细纹、细线

There was a hairline in the glaze of the old teapot.

那只旧茶壶的釉面上有一道细缝。

极细的、细微的

The X-ray showed a hairline fracture in her wrist.

X光显示她的手腕有一道细微的骨裂。