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

Bloomberg was willing to pull these experts off their day jobs both to write benchmarks for sub-agents and to help evaluate entire workflows. —Jeremy Kahn, Fortune, 28 Apr. 2026

One sub-part of God’s grace is found in the (jaw-dropping) advances science has made the past few years in immunotherapy and more. —Saleen Martin, USA Today, 27 Apr. 2026

Verb

Up front, Lukas Reichel will be going in for James Hagens on the third line and on the second power-play unit while on the back end, Jordan Harris subbed in for Mason Lohrei on the second pairing with Hampus Lindholm in Saturday’s practice at Warrior Ice Arena. —Stephen Conroy, Hartford Courant, 25 Apr. 2026

Galaxy forward Joao Klauss, who was subbed off late in Saturday’s game against FC Dallas, will undergo left foot surgery and be sidelined until after the World Cup break, Coach Greg Vanney said Wednesday. —Damian Calhoun, Daily News, 23 Apr. 2026

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