名詞 side line:

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

動詞 side line:

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