ink sac

American  

noun

1. a large gland in most cephalopods, as the cuttlefish, octopus, and squid, that is near the rectum and ejects ink at predators.

2. a flexible structure containing ink.

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Example Sentences

Again, do not puncture the digestive gland or ink sac during this process.

From Scientific American • Jul. 7, 2011

Caswell swims down several fathoms and dispatches the devilfish, slitting its ink sac with one blow of his trusty fish knife.

From Time Magazine Archive

He was brought closer, until the hideous central mass, with its cruel beaked jaw and ink sac hanging behind, was no more than a foot away.

From Astounding Stories, February, 1931 by Bates, Harry

His dispositions to fall into them made him rather like a nervous sepia that cannot keep its ink sac quiet while it is sitting for its portrait.

From The Wife of Sir Isaac Harman by Wells, H. G. (Herbert George)

The animal carried an ink sac, and no doubt used it as that of the modern cuttlefish is used,—to darken the water and make easy an escape from foes.

From The Elements of Geology by Norton, William Harmon