overgrowth vs giantism

overgrowth and giantism both are nouns.

Word	Noun	Adjective	Verb	Adverb
overgrowth	Yes	No	No	No
giantism	Yes	No	No	No

As nouns, overgrowth and giantism are synonyms defined as:

overgrowth and giantism: excessive size; usually caused by excessive secretion of growth hormone from the pituitary gland

Other synonyms of overgrowth include gigantism.

overgrowth (noun)	giantism (noun)
a profusion of growth on or over something else	excessive largeness of stature
excessive size; usually caused by excessive secretion of growth hormone from the pituitary gland	excessive size; usually caused by excessive secretion of growth hormone from the pituitary gland