Hag
To see a hag in your dream represents the “Wise Old Woman” figure and thus refers to nurturance. Negatively, to see a hag in your dream signifies the devouring mother.
Piston
To see a piston in your dream symbolises your drive, determination and ambition. You are evaluating your goals and your means to achieve them. Alternatively, the dream may also be a metaphor for sexual activity. You may be lacking passion in your sex life to the point where it has gotten somewhat mechanical.