If a history buff mentions a sub, she's probably referring to an underwater warship. But if your friend wants a sub for lunch, he hasn't suddenly developed a taste for warships — he just wants a sandwich.

Sub is short for submarine, the cylindrical watercraft with rounded ends that can operate deep beneath the water. Sub can also refer to a long sandwich filled with meat, cheese, and veggies; this kind of sub goes by different names in different parts of the country, including hero, hoagie, and grinder. The sub in your geometry classroom is probably just a substitute teacher.

Primary Meanings of sub

a submersible warship usually armed with torpedoes
be a substitute
Full Definitions of sub

n a submersible warship usually armed with torpedoes

U-boat, pigboat, submarine
show 4 types...
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attack submarine
a military submarine designed and armed to attack enemy shipping
auxiliary research submarine
a submarine for research purposes
fleet ballistic missile submarine
a submarine carrying ballistic missiles
nautilus, nuclear submarine, nuclear-powered submarine
a submarine that is propelled by nuclear power
Type of:
submersible, submersible warship
a warship designed to operate under water

n a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States

Cuban sandwich, Italian sandwich, bomber, grinder, hero, hero sandwich, hoagie, hoagy, poor boy, submarine, submarine sandwich, torpedo, wedge, zep
Type of:
two (or more) slices of bread with a filling between them

v be a substitute

fill in, stand in, substitute
Type of:
change, exchange, interchange
give to, and receive from, one another

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