"plunderer," early 14c., from obsolete verb pill "to plunder, to pillage" (see pillage (v.)).
Examples from the Web for piller
Small, long, sharp at the point, and straight as any piller.Amenities of Literature|Isaac Disraeli
Until another night in nightI enter'd, from the clearer light,Imbower'd vaults of piller'd palm.A Dweller in Mesopotamia|Donald Maxwell
And Iacob sett vp a piller apon hir graue/ which is called Rahels graue piller vnto this daye.The First Boke of Moses called Genesis|William Tyndale
I lay down agin, kivered my face with the piller, and burst out a cryin.
He worries poor Desdemony terrible by his vile insinuations, & finally smothers her to deth with a piller.The Complete Works of Artemus Ward|Charles Farrar Browne (AKA Artemus Ward)