The term 'ONE WHO GOES ON AND ON AND ON' can be summarized by two crossword solutions: BORE (4 letters) and RAMBLER (7 letters). A BORE is someone who talks excessively and tediously, often about topics that are not interesting to the listener. A RAMBLER is someone who talks at length without staying on one topic or making a point. Both terms refer to someone who talks too much and does not allow for conversation or discussion.