sheet pile vs spile

sheet pile and spile both are nouns.

Word	Noun	Adjective	Verb	Adverb
sheet pile	Yes	No	No	No
spile	Yes	No	No	No

As nouns, spile is a hypernym of sheet pile; that is, spile is a word with a broader meaning than sheet pile:

sheet pile: a pile in a row of piles driven side by side to retain earth or prevent seepage
spile: a column of wood or steel or concrete that is driven into the ground to provide support for a structure

Other hypernyms of sheet pile include pile, piling, stilt.

sheet pile (noun)	spile (noun)
a pile in a row of piles driven side by side to retain earth or prevent seepage	a plug used to close a hole in a barrel or flask
	a column of wood or steel or concrete that is driven into the ground to provide support for a structure