No it is slang. Grossvater is high German.
Grandma in German is "Oma" and grandpa is "Opa".
"Opa" is a term for grandfather in German and some other European languages like Dutch and Danish.
The High German is an official language of Germany and Austria, while Low German is the language of the Low Countries (Dutch, Flemish, and Frisian and of the northern lowlands of Germany).
The two major forms of the German language are High German (Hochdeutsch), which is the standard form of the language, and Low German (Plattdeutsch), which is spoken in Northern Germany and the Netherlands.
The word for high is the same in German. High
In German, grandpa is Großvater or Opa.
Opa also means grandfather in Dutch and German. Oma means grandmother in Dutch and German.
Großvater Opa
The High German for "Great-grandmother" is "Urgroßmutter".The colloquial usage of "Great-grandma" is "Uroma".
Grossvater, Opa
Opa Opapa Großvater
Grandfather in Austrian German translates to "Grossvater" but is also "Opa" which is more akin to "grandpa."
The common affectionate term is "Opa" for "Grandpa" and "Grandad.""Grossvater" is the formal word for "Grandfather."
Grandma in German is "Oma" and grandpa is "Opa".
Großvater = Grandfather Opa = Grandpa
Grandad is Grossvater or Opa (granpa).
u mean language..German