Crossword clues for the word: HIGHTREASON The word HIGHTREASON has appeared as an answer to at least 5 crossword clues on different crossword puzzles. Crossword clues for HIGHTREASON Showing 1 to 5 of 5 results Clue(s) Grievous betrayal Grounds for impeachment It has made many people lose their heads Lofty idealist's ultimate motive for betrayal Treachery at the top?