There are different religions in Ireland so there is no single answer to that. The leaders of those different religions would have different titles. All the main world religions in the world, like Christianity, Islam, Judaism, Buddhism, Hinduism etc., are all found in Ireland.
KHALEEFA
The word used for the head of an Irish government is the word Taoiseach, pronounced "tea - shock". It is a word from the Irish language and it is an old word meaning leader or chieftain.
Irish tricolour.
Non-religious.
Chela
neither the astronaut or the Irish leader has a middle name
Irish
Hindu Religious leader or guide is called Guru. Also many people call him Pramukh or baba.
If a given name it would stay the same; no Irish equivalent.
The fuhrer, which means The leader.
it is a Gaelic (Irish) last name.
He was given his name by Eli Muhammad (his religious leader) in late 1963 but kept it a secret until he won the heavyweight title from Sonny Liston on the 25th of February 1964.