sub

1 of 5

noun (1)

ˈsəb 

: substitute

sub

2 of 5

verb

subbed; subbing

intransitive verb

: to act as a substitute

transitive verb

1

British : to read and edit as a copy editor : subedit

2

: subcontract sense 1

sub

3 of 5

noun (2)

: submarine

sub

4 of 5

abbreviation

1

subaltern

2

subscription

3

subsidiary

4

suburb

sub-

5 of 5

prefix

1

: under : beneath : below

subsoil

subaqueous

2

a

: subordinate : secondary : next lower than or inferior to

substation

subeditor

b

: subordinate portion of : subdivision of

subcommittee

subspecies

c

: with repetition (as of a process) so as to form, stress, or deal with subordinate parts or relations

sublet

subcontract

3

: less than completely, perfectly, or normally : somewhat

subacute

subclinical

4

a

: almost : nearly

suberect

b

: falling nearly in the category of and often adjoining : bordering on

subarctic

Synonyms

Noun (1)

• substitute
• replacement

Verb

• substitute

Noun (2)

• submarine
• hero

Examples of sub in a Sentence

Noun (1)

we had a sub in English today, so we didn't get our test results back

Verb

Smith subbed for Jones at halftime.

subbing in a Broadway play

Smith subbed Jones at halftime.

Noun (2)

we shared a tuna sub at lunch

Recent Examples on the Web

Noun

These models can evaluate their own outputs better, break complex tasks into sub-tasks, and learn from feedback, potentially bringing AI closer to complex, real-world problem-solving. —Beatrice Nolan, Fortune, 30 Oct. 2025

Sorogoyen also brings a sense of sub-genre with every episode varying in tone. —John Hopewell, Variety, 30 Oct. 2025

Verb

The Hurricanes subbed in a slew of backups on both sides of the ball after that. —Jordan McPherson, Miami Herald, 26 Oct. 2025

Josh Faraimo, subbing for starting quarterback Brady Palmer, threw a TD pass to Isaac Cook. —John Maffei, San Diego Union-Tribune, 26 Oct. 2025

Word History

Etymology

Prefix

Middle English, from Latin, under, below, secretly, from below, near, from sub under, close to — more at up

First Known Use

Noun (1)

1777, in the meaning defined above

Verb

1853, in the meaning defined at intransitive sense

Noun (2)

1913, in the meaning defined above

Phrases Containing sub

• sub-adolescent
• sub-agency
• sub-agent
• sub-allocate
• sub-allocation
• sub-aqua
• sub-area
• sub-audible
• sub-average
• sub-basement
• sub-basin
• sub-block
• sub-branch
• sub-caste
• sub-ceiling
• sub-cellar
• sub-chapter
• sub-chief
• sub-clan
• sub-cluster
• sub-code
• sub-collection
• sub-college
• sub-collegiate
• sub-colony
• sub-commission
• sub-component
• sub-county
• sub-cult
• sub-dean
• sub-decision
• sub-department
• sub-development
• sub-dialect
• sub-director
• sub-directory
• sub-discipline
• sub-district
• sub-economy
• sub-faculty
• sub-file
• sub-folder
• sub-fragment
• sub-frame
• sub-generation
• sub-genre
• sub-goal
• sub-government
• sub-industry
• sub judice
• sub-language
• sub-level
• sub-lot
• sub-manager
• sub-market
• sub-maximal
• sub-maximally
• sub-menu
• sub-minimal
• sub-minimum
• sub-minister
• sub-national
• sub-network
• sub-niche
• sub-optimal
• sub-optimally
• sub-optimization
• sub-optimize
• sub-optimum
• sub-organization
• sub-panel
• sub-par
• sub-paragraph
• sub-parallel
• sub-part
• sub-period
• sub-phase
• sub-process
• sub-product
• sub-project
• sub-rational
• sub rosa
• sub-Saharan
• sub-scale
• sub-science
• sub-sea
• sub-secretary
• sub-sector
• sub-segment
• sub-sentence
• sub-series
• sub-site
• sub-skill
• sub-society
• sub-specialist
• sub-specialization
• sub-specialize
• sub-specialty
• sub specie aeternitatis
• sub-state
• sub-stellar
• sub-system
• sub-task
• sub-test
• sub-theme
• sub-therapeutic
• sub-topic
• sub-treasury
• sub-trend
• sub-tribe
• sub-type
• sub-unit
• sub-variety
• sub-visible
• sub-visual
• sub-world
• sub-writer
• sub-zero
• sub-zone

Rhymes for sub

• bub
• club
• cub
• dub
• grub
• hub
• nub
• pub
• rub
• scrub
• shrub
• snub

Kids Definition

sub

1 of 4 noun

ˈsəb 

: substitute entry 1

sub

2 of 4 verb

subbed; subbing

: to act as a substitute

sub

3 of 4 noun

: submarine entry 2

sub-

4 of 4 prefix

1

: under : beneath : below

subsoil

subfreezing

2

a

: being at a lower rank or secondary level

substation

b

: division or lesser part of

subcommittee

subtopic

c

: involving a secondary stage or process

sublet

subcontract

3

: less than completely, perfectly, or typically : somewhat

subdominant

4

: bordering upon

subarctic

Etymology

Prefix

from Latin sub- "under, below"

Legal Definition

sub-

prefix

1

: under : beneath : below

substandard

2

a

: subordinate : secondary : next lower than or inferior to

subagent

b

: subordinate portion of : subdivision of

subchapter

subcommittee

c

: assigning to another by the same method

sublicense

subcontract