What does sub mean?
“Sub” is a versatile informal English word whose meaning depends on context. Most commonly, it is a short form for a submarine, especially in discussions of naval activity, or for a subscription to a newspaper, website, or other service. In workplaces and military settings, it can also refer to a subordinate, while informal American English uses it for a sandwich made on a long roll. As a verb, “sub” means to substitute or replace someone, particularly in a team or sports context: “She subbed in during the second half.” Because its meanings are shortened versions of longer words, the intended sense must usually be inferred from the surrounding sentence. The term is generally casual rather than formal, although some uses, especially “submarine,” are standard in naval terminology.
An informal term for a submarine, a subscription, a subordinate, or, in American English, a large sandwich made with a long roll.
"The sub surfaced several miles from the shore."
The specific meaning depends on context. The sandwich sense is especially associated with informal American English.
To substitute or replace someone, especially in a sports or team context.
"The coach subbed the young defender in after halftime."
Commonly used informally, especially with the forms 'sub in' and 'sub for.'
The plural is used for meanings such as submarines, subscriptions, or subordinate people, depending on context.
"The museum displays photographs of early naval subs."
One tiny word can send you under the sea, into a subscription, or straight to lunch.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sub come from?
The word is an informal shortening of several English words, including “submarine,” “subscription,” and “substitute.” These words belong to a wider family derived from the Latin prefix sub-, meaning “under” or “beneath.” The same Latin root appears in “subordinate,” “subscribe,” and “subterranean,” reflecting ideas of being below, under, or placed beneath something.
Related word forms
How sub is actually used
The word is informal and often depends on context for its meaning. It is especially common for a submarine and a subscription, while the sandwich meaning is particularly associated with informal American English. As a verb, it is commonly used in sports to mean substitute, often in phrases such as 'sub in'.
Easily confused with sub
As a noun, a sub usually refers to a submarine, a subscription, or a subordinate, while a substitute is someone or something that takes the place of another.
A sub is the informal short form of subscription, whereas subscription is the full standard term for payment or access to a continuing service.