(sometimes written as two words: 'green inker') A member of the green ink brigade: in British journalistic circles, these are crackpots who write letters to the editors of newspapers or to celebrities, highlighting important words and phrases by using different coloured (typically green) ink. They may also write the whole letter in a coloured ink.
A famous novelist, read the first line of a letter, which began 'Lynda, you rotten swine..' and thought: "Oh no, a greeninker!" but reading on she realised it was a friend expressing mock jealousy over a recent success of hers.
by Wally Greeninker January 5, 2015