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 of sub

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

Still, researchers emphasize that K2-18b remains a high-value target for understanding sub-Neptunes, a class of planets absent from our solar system. —Sharmila Kuthunur, Space.com, 26 Dec. 2025

The new sub wasn’t the only hint of North Korea’s future that emerged in the images released Thursday. —Brad Lendon, CNN Money, 25 Dec. 2025

Verb

After the quartet of Garza, Gonzalez, Simons, Minott subbed in, Boston ripped off an 18-3 run to take a 32-20 lead. —Zack Cox, Boston Herald, 21 Dec. 2025

Backup Tank Bigsby subbed in, and, two plays later, took one cut up the field to finish what Barkley started with a 22-yard touchdown — his first since joining the Eagles by trade in September. —Brooks Kubena, New York Times, 21 Dec. 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