In the English origin, Donnan means "Donnan \d(on)-nan\ as a boy's name is a variant of Don (English). See for meaning of Donnan.
The baby name Donnan sounds like Tannan, Danon, Tannon, Tannen, Tannin, Tynan, Tynnin, Tynnen and Tienan. Other similar baby names are Annan, Cannan, Conan, Dontay, Dontae, Donau, Denman, Doan, Dolan, Donny, Donnie, Donne, Donn, Donnel, Donal, Donovan, Donavan, Doran, Dorran, Dorian, Dowan, Dougan, Doogan, Duncan, Kannan, Kennan and Ronan."
In the Irish origin, Donnan means "Brown"