There are 2 main definitions of sac in English:

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sac 1

Pronunciation: /sak/


1A hollow, flexible structure resembling a bag or pouch: a fountain pen with an ink sac
More example sentences
  • Rain Reviva is a system of flexible plastic sacs for storing rainwater - or recycling waste water - under the house.
  • As the air filled the sac, the balloon took on an impossibly long shape.
  • Reseal the plastic sac and leave it rocking for 1 h at room temperature.
bag, pouch, bladder, blister
technical bursa, acinus, follicle, cyst, saccule, utricle, vesicle, vesica, vesicula, theca, liposome
1.1A cavity within an organism, enclosed by a membrane and containing air, liquid, or solid structures.
Example sentences
  • In the field of biology, biochemists have been studying vesicles, the small membrane sacs found within cells.
  • Fistulas commonly extend from the rectal sac to the perineum or genital tract in a female, or to the urinary tract in a male.
  • If chemicals are splashed into the eye, the eye and the conjunctival sacs should be washed out immediately with copious amounts of water.
1.2The distended membrane surrounding a hernia, cyst, or tumour.
Example sentences
  • If the leak persists or the aneurysmal sac enlarges, intervention becomes necessary.
  • In the vicinity of this mass, there was a hernia sac.
  • As people get older, fluid-filled sacs, called ‘cysts,’ can form in the kidneys.



Example sentences
  • The cnidarians (hydra, jellyfish, and sea anemones) and helminths have a sac-like digestive system with a single opening.
  • Chlorosomes, found only in green photosynthetic bacteria, are large supramolecular sac-like complexes that are attached to the cytoplasmic side of the inner cell membrane.
  • The saccular or cystic form is the most severe type and is characterized by a ballooning of the bronchi with fluid-filled, sac-like dilatations.


Mid 18th century (as a term in biology): from French sac or Latin saccus 'sack, bag'.

Words that rhyme with sac

aback, alack, attack, back, black, brack, clack, claque, crack, Dirac, drack, flack, flak, hack, jack, Kazakh, knack, lack, lakh, mac, mach, Nagorno-Karabakh, pack, pitchblack, plaque, quack, rack, sack, shack, shellac, slack, smack, snack, stack, tach, tack, thwack, track, vac, wack, whack, wrack, yak, Zack
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There are 2 main definitions of sac in English:

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Senior Aircraftman or Senior Aircraftwoman.
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