dispa-rage can be read as display a rage. When you display your RAGE on your juniors you BELITTLE them in front of the others.
dis-opposite, parage-praise so if u don't praise 4 someone u criticize him.
disparage~discourage : when you give negetive comments/opinions about the effort put by people around you they get DISCOURAGED!
CAN REMEMBER AS disprin - which DEPRECIATES(DEGRADES, REDUCES) THE PAIN.
we DISPARAGE a 10-paisa coin
we know Disparity=inequality or difference in some respect... same Disparage=belittle someone..