James Gasik
We don't talk about Pun-Pun
Wrist razors from Athas are blades attached to a forearm bracer. 3e had armor spikes that could be used to make attacks. I don't know if D&D ever had it, but Pathfinder had the Dwarven Boulder Helm, specifically designed to head butt someone. 3.5 had the Dwarven Buckler-Axe, strapped to the forearm.I agree that you would be wearing it.
I do not believe it is natural language to say you are carrying it.
I suppose there may be a way in 5e to wield something without using hands. I'm not familiar with techniques for holding a shield with teeth or feet, but it is a fantasy game, so I'm open to hearing how such an idea may work.
So weapons that don't require the actual use of the hand could exist in the game. Not that I expect to see them, 5e's "vision" doesn't seem to include exotic weaponry.