parergon
/pæˈrɜːgɒn/noun
(pl. parerga /-gə/)
1- a piece of work that is supplementary to or a by-product of a larger work附件; 副产品。
1.1
- archaic work that is subsidiary to one's ordinary employment〈古〉（本职工作以外的）副业工作：
he pursued astronomy as a parergon.
他把研究天文作为副业。
词源
early 17th cent.: via Latin from Greek parergon, from para- 'beside, additional' + ergon 'work'.