sideline

Like most other fishes, the dragonet varies slightly in colour in different individuals, and at different seasons of the year. Mr. Pennant describes the pupils of the eyes to be of a rich sapphirine blue; the irides fine fiery carbuncle; the pectoral fins light brown; the side-line straight; the colours of the fish yellow, blue, and white, making a beautiful appearance when fresh taken.

She started the business as a sideline to her regular work and it ended up becoming the greater source of income.

The coach stood on the sidelines and bellowed commands at the team.

She installed the whole fixture while he simply watched from the sidelines.