what heather said - as a mdidle name. I think that a first name should be unique to the baby, but middle names can be 'for' someone. I also especcially like using maternal family names for the middle names. Given The paternal name is usually the last name.

We used my maiden name for my daughters middle name, and my grandfathers name for my sons middle name (which is also one of my dads middles names)...my dad hates it...but he was chuffed that we used it. My dad was only 3 when his dad dies, so has no memories of him, and by total coincidence my son was born within 2 hours of my granddads birthday! So that was kind of nice.

And since middle names are rarely used, your granddad probably wouldn't mind so much...chuffed is a good word!

Hope you have a son one day! xo