A dark liquid ejected for protection by most cephalopods, including octopuses and squids, A pigmented liquid or paste used especially for writing or printing, A mixture of lampblack and turpentine used with a brush or stencil for marking packing-cases and other packages, verb_ append one's signature to, fill with ink, transitive verb_ To mark, coat, or stain with ink, Informal To append one's signature to (a contract, for example)