Where does “Callan” come from?

Callan derives from Irish Ó, a prefix meaning "descendant of," though the specific personal name it originally modified remains unattested.

Ancestry of “Callan”, step by step

StepLanguageWordMeaning
1IrishÓ Cathaláin
2IrishCathalánlittle Cathal
3Old IrishCathal
4Proto-CelticKatuwalosstrong in battle
5Proto-Celtickatusbattle
6Proto-Indo-Europeankéh₃tusfight
7Proto-Indo-European-tusDerives action nouns from verb roots

Words derived from “Callan

Every word from Proto-Indo-European -tusEvery word from Proto-Indo-European kéh₃tusEvery word from Proto-Celtic katus