sideline

名词 sideline:

1. a line that marks the side boundary of a playing field
   同义词：out of bounds
2. an auxiliary line of merchandise
3. an auxiliary activity
   同义词：avocation, by-line, hobby, pursuit, spare-time activity

动词 sideline:

1. remove from the center of activity or attention; place into an inferior position

1. Actually I'm a teacher, my writing is just a sideline.
   我其实是个教师，写作只是我的兼职。
2. I was on the sidelines during the political crisis.
   在这一政治危机时期我是目睹一切的局外人。