Where does “Popielarz” come from?

Popielarz (Polish) comes from Polish -arz, from Old Polish -arz, from Proto-Slavic -ařь, from Gothic -𐌰𐍂𐌴𐌹𐍃, from Proto-Germanic -ārijaz, from Latin -ārius, from Proto-Italic *-āzios — Forms relational adjectives to nouns (and rarely numerals).

Popielarz (Polish): a worker responsible for removing ash and slag

Definitions

a worker responsible for removing ash and slag

Ancestry of “Popielarz”, step by step

Step	Language	Word	Meaning
1	Polish	-arz	-er
2	Old Polish	-arz	forms agent nouns
3	Proto-Slavic	-ařь	-er
4	Gothic	-𐌰𐍂𐌴𐌹𐍃	-er
5	Proto-Germanic	-ārijaz	-er
6	Latin	-ārius	er
7	Proto-Italic	*-āzios	Forms relational adjectives to nouns (and rarely numerals)

Every word from Proto-Italic *-āzios →Every word from Latin -ārius →Every word from Polish -arz →