The definition of set-in is parts which are made separately and then placed together.
An example of set-in used as an adjective is a dress with set-in sleeves.
made as a separate unit to fit within another part: a set-in sleeve
- Made or placed as a part of another unit or structure: a set-in stereo cabinet.
- Made separately and stitched into the main part: a dress with set-in sleeves.
Material, as for a book, that is inserted; an insert.
(third-person singular simple present sets in, present participle setting in, simple past and past participle set in)
- To take root, become established.
- That was the point at which the rot set in.