KUPKA: small pile, mound or stack (diminutive of kupa); also euphemism for excrement/bowel movement; possibly orignated as a topo nick from such places as Kup, Kupce, Kupin or similar.
Some 2,600 users in Poland, around 1,500 of them in the neighbouring Katowice and Opole areas of Śląsk (SIlesia).
Kupa ludzi (a lot of men) here, including myself, did not bother to lookup standard dictionaries. But I know that "kupa" also means a group, "skupiać" means to gather together. In this sense it is thought to be a root of "Kupała (deity and Night" - other possible roots of "Kupała" are "to bath" or indoeuropean "kup-" "to desire". And obviously "kupka" in Polish is a diminutive of "kupa".
The word "kupa" was also used to describe irregular military units, plundering the country. The Lisowski's light riders were recruited from such "kupy swawolne". "Kupą, mości panowie!" was their battle cheer.
In Hungarian and Serbo-Croatian it means a cup, a goblet (from Italian "coppa"), in Slovene - a beaker, in Swedish - a hood, a cup (of bra).