What’s the difference between the two? Isn’t that like calling water Oxygenic acid?
Hydrogen chloride is a gas and a molecular compound. Hydrochloric acid is hydrogen chloride in aqueous form - in water, the hydrogen ions dissociate to create an acid.
So when the label on the toilet bowl cleaner (clearly a liquid) says “active ingredient: Hydrogen chloride, 9.05%” it’s really good old HCl?
Yes, hydrochloric acid is an aqueous solution of hydrogen chloride. Sometimes it’s called muriatic acid, but it’s all just HCl in water.
No, no, water is hydrogen dioxide, the most dangerous substance in the universe. 
Actually, that’s dihydrogen monoxide. Its H[sub]2[/sub]O, not HO[sub]2[/sub]