slews vs piles

slews and piles both are nouns.

Word	Noun	Adjective	Verb	Adverb
slews	Yes	No	No	No
piles	Yes	No	No	No

As nouns, slews and piles are synonyms defined as:

Other synonyms of slews include dozens, gobs, heaps, lashings, loads, lots, oodles, rafts, scads, scores, stacks, tons, wads.

slews (noun)	piles (noun)
a large number or amount	a large number or amount
	venous swelling external or internal to the anal sphincter