An informal, affectionate term for a grandfather; a variant of grandpa with more emphasis or formality than grandpap.
From grand- plus papa (itself from Latin papas or similar childish forms found in Indo-European languages). This spelling emphasizes the 'papa' component and was more common in 19th-century English.
Grandpapa sounds so formal and old-fashioned to modern ears, but it was actually the way Victorian children referred to grandfathers—you'd hear it all through the 1800s and early 1900s!
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