DROP is the main command used for discarding items from your inventory along with PUT for placing items from your inventory/within arm's reach into containers or boxes or wagons.

Syntax: DROP <item>

Discards the specified item, placing it on the ground.

Syntax: PUT <item> IN <container>

Places the specified item into the container you designed. This container needs to be a suitable item type like a box, sack, wagon etc.

See also HELP INVENTORY, HELP HOLDING, HELP INFO, HELP WAGONS and HELP OBJECTS for command syntax list.