I've seen Maddock before, so I think it could be a real name. However, it's not my style at all. I don't care for Maddock, Maddox,
Madoc, or
Madog, sorry.
Maddock comes from
Madoc, which is a Welsh name meaning "fortunate", like I said. So Maddock's meaning would be "fortunate".
Keelan actually means "slender and fair" because of the two elements meaning "fair" and "slender" respectively are combined in the name
Caoilfhionn.
Keelan is an Anglicisation, or English version, of
Caoilfhionn.
Oxygen.com's Babynamer (
http://tools.oxygen.com/babynamer/) is another fairly accurate site. However, it does get meanings wrong occasionally.
Miranda