Definitions of ink:

• noun:   dark protective fluid ejected into the water by cuttlefish and other cephalopods
• noun:   a liquid used for printing or writing or drawing
• verb:   fill with ink

  Example: "Ink a pen"

• verb:   append one's signature to

  Example: "They inked the contract"

• name:  A surname (very rare: popularity rank in the U.S.: #71741)