The term 'Put One's John Hancock On' is an idiom that means to sign a document. This phrase is derived from the signature of John Hancock, who was one of the first people to sign the Declaration of Independence. The crossword solutions for this term are INKED (5 letters), INK (3 letters), and SIGNED (6 letters). INKED means to cover with INK, while INK is a liquid used for writing or printing. SIGNED means to have written one's name on a document as a form of agreement.