is piles common noun

Yes, the Word 'piles' is a noun; a plural, uncountable noun as a Word for hemorrhoids.

The Word 'piles' is also a countable noun (pile, piles) and a verb (pile, piles, piling, piled).

The countable noun 'piles' is a Word for heaps of things laid one on another; a Word for large strong posts driven into the ground to support a building or other structure.

The noun 'pile' is a singular, uncountable noun as a Word for the surface texture of carpet or cloth.