threshold vs showtime

threshold and showtime both are nouns.

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

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

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

threshold (noun)	showtime (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 time at which something is supposed to begin
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 smallest detectable sensation
a region marking a boundary
the starting point for a new state or experience