yī​dìng HSK2

surely

一定 yī​dìng
surely adverb
surely, certainly, necessarily, or expressing a requirement (must)

You must come to the meeting tomorrow.

a certain adjective
to a certain extent, degree, or level; some amount of

To some extent, this article reflects reality.

fixed adjective
fixed, specified, given, or particular

The rules here are fixed and cannot be changed at will.

Frequency

Movie subtitles
604.3 per million appears in 84% of films
Written text
489.4 per million

Details

HSK 2.0
Level 3
HSK 3.0
Level 2

Sources

Definitions
CC-CEDICT