outgrowth vs beginning

outgrowth and beginning both are nouns.

Word	Noun	Adjective	Verb	Adverb
outgrowth	Yes	No	No	No
beginning	Yes	Yes	No	No

As nouns, beginning is a hypernym of outgrowth; that is, beginning is a word with a broader meaning than outgrowth:

outgrowth (noun)	beginning (noun)
a natural prolongation or projection from a part of an organism either animal or plant	the act of starting something
the gradual beginning or coming forth	the first part or section of something
a natural consequence of development	the event consisting of the start of something
	the place where something begins, where it springs into being
	the time at which something is supposed to begin

outgrowth (adjective)	beginning (adjective)
	serving to begin