A liquid used for printing or writing or drawing WordNet 3.0 & Open English WordNet

Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, or design. Wikipedia

Liquid containing pigments or dyes used for drawing, writing or printing. Wikipedia Disambiguation

Liquid or paste that contains pigments or dyes Wikidata

A dispersion of a pigment or a solution of a dye in a carrier vehicle, yielding a fluid, paste, or powder to be applied to and dried on a substrate; writing, marking, drawing, and printing inks are applied by several methods to paper, metal, plastic, wood, glass, fabric, or other substrate. OmegaWiki

A pigment (or dye)-based fluid used for writing, printing etc. Wiktionary