spile vs sheet piling

spile and sheet piling both are nouns.

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

As nouns, sheet piling is a hyponym of spile; that is, sheet piling is a word with a more specific, narrower meaning than spile:

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

Other hyponyms of spile include sheath pile, sheet pile.

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