n .
something added to or connected with something else ; an assistant 다른 것에 부가되거나 연결되어 있는 것 ; 보조물

• Cooking is just an _____ to Michael's real hobby, which is eating.
• The enthusiastic publisher released a set of audiotapes as an _____ to its popular series of vocabulary books.
• An _____ professor is one who lacks a permanent position on the faculty.