Overmuch vs Monstrous - What's the difference?

As a determiner overmuch

is very much; too much.

is too much; overly much.

hideous or frightful.

(en determiner)

(chiefly, British) very much; too much

* 1990 , , Britain's defence dilemma: An inside view (rethinking British defence policy in the post-imperial era) , page 78,

This seemed to me a more important priority in 1959 than overmuch argument about nuclear philosophical heresies of one kind or another.

(chiefly, British) too much; overly much

Some readers do not care overmuch for poetry.

(en adjective)

hideous or frightful

* Shakespeare

So bad a death argues a monstrous life.

enormously large

a monstrous height

a monstrous ox

freakish or grotesque

* John Locke

a monstrous birth

* Jeremy Taylor

He, therefore, that refuses to do good to them whom he is bound to love is unnatural and monstrous in his affections.

of, or relating to a mythical monster; full of monsters

* Milton

Where thou, perhaps, under the whelming tide / Visitest the bottom of the monstrous world.

(obsolete) marvellous; strange

* See also