QUOIN is a playable word

quoin Scrabble® Dictionary

verb
quoined, quoining, quoins
to secure with a type of wedge
11 Playable Words can be made from "QUOIN"
   2-Letter Words (7 found)
   3-Letter Words (2 found)
   4-Letter Words (1 found)
   5-Letter Words (1 found)