hide OBJECT
This will attempt to move an item from your inventory into the room unseen. OBJECTs hidden in the room will be revealed with the search command.

hide OBJECT [on YOURNAME] [in CONTAINER]
This will attempt to hide an object on yourself, or in a container. Objects that are hidden cannot be stolen.

Success of hiding an object is based on your thievery skill. It is possible others might catch you acting suspiciously when you try to hide something.