jí​diǎn

extreme point

极点 (極點) jí​diǎn
extreme point noun
the highest or furthest point; the limit or extremity of something

His exhaustion has reached its limit.

origin noun
the fixed reference point in a polar coordinate system

In a polar coordinate system, the pole is usually represented by the letter O.

Frequency

Movie subtitles
2.35 per million appears in 1% of films
Written text
4.71 per million

Sources

Definitions
CC-CEDICT