transitive verb
1. : to put in : insert ; especially : to stitch (a small part) within a large article
set in a sleeve of a dress
set in a belt at the waistline
2. : to direct (a ship) towards shore
intransitive verb
1. : to enter upon a particular state : become prevalent or settled
cold weather set in before the British could take the forts — E.P.Alexander
2. dialect : to set to work : begin to function
3. : to blow or flow toward shore
the wind was beginning to set in