Over and Overmuch

Over adverb - From one side to the other of an intervening space.

Overmuch and over are semantically related in in addition topic. In some cases you can use "Overmuch" instead the word "Over" as an adverb or an adjective.

Overmuch adverb - Beyond a normal or acceptable limit.

Over and overmuch are semantically related in excessive topic. Sometimes you can use "Over" instead the word "Overmuch" as an adverb or an adjective, if it concerns topics such as unduly.