覆う【おおう】
to cover, to hide, to conceal, to wrap, to disguise
覆す【くつがえす】
to overturn, to capsize, to upset, to overthrow (government etc.), to reverse (decision etc.), to disprove (an established theory etc.), to overrule
覆面【ふくめん】
mask, veil, disguise, anonymous, unmarked, incognito
覆る【くつがえる】
to topple over, to be overturned, to capsize, to be overruled, to be reversed, to be discredited