sac

1 of 4

noun

ˈsak 

: a pouch within an animal or plant often containing a fluid

a synovial sac

saclike

ˈsak-ˌlīk 

adjective

sac

2 of 4

abbreviation (1)

sacrifice

Sac

3 of 4

variant of sauk

SAC

4 of 4

abbreviation

1

special agent in charge

2

Strategic Air Command

Examples of sac in a Sentence

Recent Examples on the Web

Noun

In pneumonia, the lung sacs where air is exchanged, called alveoli, become inflamed and filled with pus and fluid. —Judy Stone, Forbes, 22 Feb. 2025

An epidural block is injected into the space outside of the sac of fluid around the spinal cord called the epidural space. —Femi Aremu, Verywell Health, 10 Sep. 2024

Male Darwin’s frogs actually carry tadpoles inside their vocal sacs as a protective act while the larvae metamorphose into froglets. —Ashley Strickland, CNN, 8 Feb. 2025

The joints—and the sacs between each one—allow the skeleton to shift and withstand pressure, even if that particular joint isn’t helping anyone do a backbend. —Bethany Brookshire, Scientific American, 25 Jan. 2025

Word History

Etymology

Noun

French, literally, bag, from Latin saccus — more at sack

First Known Use

Noun

1741, in the meaning defined above

Phrases Containing sac

• air sac
• amniotic sac
• cul-de-sac
• embryo sac
• honey sac
• pollen sac
• sac bunt
• sac fly
• sac fungus
• yolk sac

Rhymes for sac

• ack
• brack
• clack
• crack
• dak
• flack
• flak
• hack
• jack
• knack
• lac
• lack

Kids Definition

sac

noun

ˈsak

: a pouch in an animal or plant often containing a fluid

a food-storage sac

saclike

-ˌlīk

adjective

Medical Definition

sac

noun

ˈsak 

: a soft-walled anatomical cavity usually having a narrow opening or none at all and often containing a special fluid

a synovial sac

see air sac, amniotic sac, dental sac, lacrimal sac