Denshi Jisho — Online Japanese dictionary

覆す くつがえす to overturn; to upset; to overthrow; to undermine
Common word, Godan verb with su ending, Transitive verb 

You can also

Look up kanji details for 覆す.

Try a Yahoo Jisho search for 覆す .
Try a Goo Jisho search for 覆す .
Try a Google search for 覆す .