Chipper refers to a person who smokes cigarettes only occasionally; a social smoker. 

“社交吸烟者”指的是偶尔吸烟的人，一般是在社交场合。

Chippers are able to smoke just a few cigarettes regularly but never become pack-a-day smokers. 

“社交吸烟者”能够做到定期吸几支烟，而从不会变成大烟枪。