threshold vs beginning

threshold and beginning both are nouns.

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

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

Other hypernyms of threshold include commencement, first, get-go, kickoff, offset, outset, showtime, start, starting time.

threshold (noun)	beginning (noun)
the sill of a door; a horizontal piece of wood or stone that forms the bottom of a doorway and offers support when passing through a doorway	the act of starting something
the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close	the first part or section of something
the smallest detectable sensation	the event consisting of the start of something
a region marking a boundary	the place where something begins, where it springs into being
the starting point for a new state or experience	the time at which something is supposed to begin

threshold (adjective)	beginning (adjective)
	serving to begin