Other forms: inks
Ink is the dark cloud a squid releases to escape. Squirt ink, a cloud of ink, inky water.
It is not only a smokescreen: it contains a compound that dulls a predator's sense of smell, and some squid release a blob roughly their own size to be attacked instead. The writing sense is the older one in English. Note that the word comes from a Greek term for a burned-in purple ink used by emperors.
Old French enque comes from Latin encaustum, the purple ink Roman emperors signed with, from Greek meaning burned in.
Middle English
ynke
English, today
ink
Built from
From Middle English ynke. From Middle English ynke, from Old French enque, from Latin encaustum (“purple ink used by Roman emperors to sign documents”), from Ancient Greek ἔγκαυστον (“burned-in”), from ἐν (“in”) + καίω (“burn”). In this sense, displaced native blæc. Sense four refers to the ink used in newspapers.
Etymology from Wiktionary, CC BY-SA