Ferdinand I
1 of 3biographical name (1)
Fer·di·nand I ˈfər-də-ˌnand 
1016(or 1018)–1065 the Great king of Castile (1035–65); of León (1037–65)
Ferdinand I
2 of 3biographical name (2)
1503–1564 Holy Roman emperor (1558–64)
Ferdinand I
3 of 3biographical name (3)
1861–1948 king of Bulgaria (1908–18)
- gray iron
- gray ironbark
- gray jay
- gray jumper
- gray kangaroo
- gray kingbird
- Gray Lady
- gray leaf
- gray leaf spot
- gray lemming
- gray literature
- gray mallard
- gray manganese ore
- gray market
- gray matter
- gray Minyan ware
- gray mold
- gray mold rot
- gray moss
- gray mullet
- gray nerve fiber
- gray nun
- gray nurse
- gray nurse shark
- gray oak