rèn​yì HSK7

any

任意 rèn​yì
any adjective
no matter which one is chosen; arbitrary in a logical or mathematical context

A straight line can be drawn between any two points.

at will adverb
as one pleases; according to one's own wishes or without restraint; at random

We cannot pick flowers at will in the park.

Frequency

Movie subtitles
5.28 per million appears in 3% of films
Written text
23.1 per million

Details

HSK 2.0
Level 6
HSK 3.0
Level 7

Sources

Definitions
CC-CEDICT