Is a torpedo a missile?

Merriam-Wester defines a missile as an object (such as a weapon) thrown or projected usually so as to strike something at a distance - stones, artillery shells, bullets, and rockets are missiles. Common usage indicates that missiles travel through the air, like the artillery shells or rockets. Although a torpedo could fit under the above definition, it is not normally considered a missile. 

However, there are missiles that can deliver a torpedo through the air to the water near a target. To further cloud the question, modern submarines can launch both advanced capability torpedoes and Tomahawk missiles from the same torpedo tubes. The newest submarines often have vertical tubes to store and launch Tomahawks and other missiles. They wouldn’t always need to launch missiles through the horizontal torpedo tubes.