cháng​kè

regular

常客 cháng​kè
regular noun
a person who visits a place frequently; a frequent visitor or patron

He is a regular at this bookstore, visiting two or three times a week.

frequent fixture noun
something that appears or crops up frequently in a particular context

These kinds of minor mistakes are common in the essays of beginners.

Frequency

Movie subtitles
4.47 per million appears in 2% of films
Written text
1.77 per million

Sources

Definitions
CC-CEDICT