The English word father has come from the Proto-Indo-European root pəter – which is also related to Sanskrit pitar (पितर), Greek and Latin pater and Old Farsi pita.
The Greek word for father is pappas, from which we get papa, pope and papal – which means ‘relating to the pope’ – as in papal blessings or papal audience. A related Greek word patria, which meant family, has given us patriarch. Originally used for the male head of a family/tribe, it is now also used figuratively to refer to the founder of an institution, society etc. or to the oldest man in a village or community. Patriarchy, though, has come to refer to a system of society in which men hold most of the power and women are largely excluded from it.
The Latin word patria took on the sense of one’s fatherland or native country. Thus an expatriate is someone who lives in a foreign country and to repatriate someone (for example refugees or prisoners of war) is to return them to their native country. A fellow citizen or someone who has the same nationality is, similarly, called compatriot – which is related to patriot (someone who supports and defends their country or ‘fatherland’).
A related word, patrimony, refers to an inheritance (esp from one’s father or ancestor). It can also be used to refer to an endowment of a church (or other institution). The custom of a new couple living with the husband’s family is called patrilocal. Killing one’s father, seen as one of the most heinous crimes in ancient societies, is called patricide.
Another related Latin word patricius means ‘of a noble father’ and patrician thus came to mean a person of ‘noble’ birth or an aristocrat (as opposed to plebeians or the ‘common folks’ such as farmers, craftsmen, laborers and soldiers).
Latin patronus (also the name of a defensive charm in the Harry Potter series) means protector or defender and gives us the word patron, as in, patron saint (saint who protects) or patron of arts (promoter, sponsor). It is now also used more generally to mean a customer. To patronize, though, has both positive and negative connotations. It can be used in a positive sense (patronize the new art gallery) to mean be a regular customer of (or support) and in a negative sense (as in, he spoke in a patronizing tone) to mean to speak down to or behave condescendingly. Compere (person who hosts formal occasions/shows, introduce other speakers and so on) comes from Lt compater and was originally used in the sense of ‘godfather’. The modern day compere, of course, godfathers/manages shows and ceremonies.
Sanskrit पितर, as you may know, refers to fathers or ancestors and पितरौ to father and mother together. Similarly, पितामह and पितामही refer to grandfather and grandmother respectively and पितृभूमि to one’s country or fatherland. Can you think of other words that are related to पितृ (father) in your language?