Skip to main content
sub

sub

133 5.8
A ship that travels under water, often used by the navy
  • noun
  • /sʌb/
  • Informal
translation icon : submarino
  • Apparently overcrowded on its test run, the sub took on water through an open torpedo bay and sank.

So you can fire one Trident out of a sub.

Autoplay Next

Examples

  • The United States Navy launched a new sub designed for deep-sea exploration.

  • We got to get the sub on deck.

  • But here inside the sub the situation is very serious.

  • We have to get on that sub.

  • And thank you for the map of Dr. Evil's sub.

  • We need to get to that sub or we'll all be 20,000 leagues under the sea.

  • How could she know how to operate a 30-year-old Russian sub?

  • On the screen: the red blip representing the sub is headed right toward a building.

    Fiction book (1996)
  • During the training exercise, the sub successfully evaded all detection by enemy ships.

  • The marine biologists boarded the sub to study the underwater ecosystems.

Synonyms

submarine
vssub
191 4.2

A warship that travels underwater and carries torpedoes

has the same meaning but is the standard main entry form
U-boat
vssub
17 8.7

A German military submarine from World War I and World War II

is the general military underwater vessel term, not limited by nationality or era
nuclear submarine
vssub
  • Specialized
9 3.6

A military submarine that runs on nuclear power and can stay underwater for months

is the general combat underwater ship concept rather than propulsion specific
nautilus
vssub
4 9.0

A submarine that uses nuclear power to move underwater

is the general military underwater vessel concept, not a specific famous example
attack submarine
vssub
  • Specialized
2 5.5

A military ship that travels under water to find and destroy enemy ships

is broader, covering any armed military underwater vessel rather than only hunters
minisub
vssub
  • Specialized
1 8.6

A very small underwater boat for one or two people used by the navy and scientists

refers to full sized military combat vessels rather than tiny craft
nuclear-powered submarine
vssub
  • Specialized
1 4.9

A military ship that uses nuclear power to stay underwater for long periods

is the generic military underwater vessel term, not focused on propulsion type
pigboat
vssub
  • Archaic
9.9

A small early submarine used in war and often armed with torpedoes

is the general modern military underwater vessel term rather than a historical type
submersible warship
vssub
  • Specialized
8.4

A military ship that can go underwater to attack or stay hidden

is broader, including all armed underwater vessels not only stealth attack craft
9.6

A large submarine that carries nuclear missiles to stop enemies from attacking a country

focuses instead on armed underwater vessels generally, not missile delivery roles
minisubmarine
vssub
  • Specialized
7.4

A very small underwater boat that carries one or two people

is larger in scale and usually denotes full military combat capability
auxiliary research submarine
vssub
  • Specialized
6.8

A submarine that helps scientists study the sea and collect samples

denotes armed military underwater vessels used for combat rather than research

Idioms

sub rosa
  • Formal
1 9.9

In a secret way to keep something private

9.9

A joking mock-Latin phrase that says 'always wear underwear' to make people laugh

Compounds

The part of Africa that is south of the Sahara Desert

sub-assembly
  • Specialized
1 7.1

A group of parts put together to fit into a larger product

sub judice
  • Jargon
9.9

Being considered by a judge or court and not open to public discussion

sub-interval
  • Specialized
7.6

A smaller interval that lies entirely inside a larger interval

sub-test
  • Specialized
4.4

A shorter test inside a larger exam, like reading or vocabulary

How Big

sub
  • Informal
133 5.8
minisubmarine
  • Specialized
7.4

Surface Forms

sub singular
subs plural

Etymology

Sub is short for submarine, a word that means 'under the sea'. So a sub is a boat that goes below the water, which is why navy underwater vessels are called subs.