亘
gèn
extending all the way across
running all the way through
Two bounds (二) + sun (日) spanning between = extending all the way across
The sun (日) is sandwiched between two horizontal lines (二), evoking the image of something stretching continuously from one boundary to another — like the sun's arc spanning the whole sky. Together they suggest an unbroken span across all of time or space.
二The number twoSemantic
日The sunSemantic
这条河亘古以来就在这里。
zhè tiáo hé gèn gǔ yǐ lái jiù zài zhèlǐ。
this river has been here extending all the way through ancient times.
一道山脉亘于南北两地之间。
yī dào shānmài gèn yú nán běi liǎng dì zhī jiān。
a mountain range runs all the way through between the land to the south and north.