borax
Concise Oxford English Dictionary © 2008 Oxford University Press:
borax /ˈbɔːraks/
▶noun a white mineral consisting of hydrated sodium borate, found in some alkaline salt deposits and used in making glass and as a metallurgical flux.
– origin ME: from med. L., from Arab. būraḳ, from Pahlavi būrak.
'borax' also found in these Oxford entries:

