Once clothing has been purchased and worn, it would be considered used clothing. If clothing is tried on in a dressing room at a store, but not sold it would still be considered new clothing.
When used clothing is being donated or sold it is considered second hand clothing.
Apparel, shoes or fashion accessories can be donated, sold or traded as used products after the original owner wishes to dispense of the items.
Used Children's Clothing Stores - popular because growing children grow out of clothing quickly.
Only retailers such as Etsy, eBay, and others help buyers & sellers transact for used fashion items.
Learn about consignment & thrift shops.
You may want to also learn about vintage fashion & vintage footwear which is essentially used clothing which is very old.
Some used clothes would be stylish and some used clothes will be out of fashion but still very wearable.