The Irish noun Ó (with an accent ABOVE) means descendant/grandson. It has been and is confused with the contraction of the preposition O' as in jack o'lantern. Bottom line is, our names never should have had an apostrophe but an O with an accent above! Ó.
A few words about prefixes: Mac is the Gaelic word for son and is sometimes written Mc, despite the widely held notion that Mac is Irish and Mc is Scottish. Both are found in the two Gaelic national traditions. O is really a word all by itself, signifying grandson. The apostrophe that now usually appears after it is simply the result of a misunderstanding by English-speaking clerks in Elizabethan time, who took it to be a form of the word of. That other distinctively Irish prefix, Fitz, derives from the French word fils, meaning son.
Here is and example of another type of problem with the original gaelic surnames and how they were recorded. In the Griffith's Valuation which was a (1852 era) mandated survey by the British Government; all my O'Connor relatives were listed as Connor. Believe me, no one in our family ever referred to themselves that way ever, it was a source of pride for them not to. Despite being one of the most numerous names in Kerry; there were no O names in the Griffith's for the part of Kerry I was researching; because the British establishment wanted to anglicize the Irish and taking off the O was one way to marginalize them; besides trying to force/coerce them to change their language and their religion of course in a variety of ways. It was the record takers that took off the O in the records I searched.
In addition in case you had any doubts, those very same "Connors" I researched from my family that were listed in the Griffith's were all O'Connor in the church records of baptisms and marriages ... at least the Priests were Irish and many spoke Gaelic so they were more likely, but not always to spell the name closer to the original. There were some priests that thought it beneficial to go with the flow and anglicize the names, so they may have altered them on their own also. You can tell by the records if you see any names at all with O or Mac. Remember too, any of the versions of these names you see were approximations of the Irish Gaelic names where they were originally from anyway. i.e. O'Connor = Ó Conchubhair. My family in Kerry spell the name Ó Conchuir, they still speak Irish as their first language.
If you are interested in the history of events as to why our ancestors were forced to lose their language and how so many were uneducated peasants or why they may not have been able to read or write or why they may have changed their names or their religions ... read a bit of this:
"In 1695 harsh penal laws were enforced, known as the 'popery code': Catholics were prohibited from buying land, bringing their children up as Catholics, and from entering the forces or the law. Catholics could no longer run for elected office, purchase land, or own property (such as horses) valued at more than 5 pounds. In the early years of the 18th century the ruling Protestants in Ireland passed these laws designed to strip the "backwards" Catholic population of remaining land, positions of influence and civil rights.
By 1778 Irish Catholics would own a meager 5% of Irish land. Furthermore, the Catholic educational system was outlawed and priests who did not conform to the laws could be branded on the face or castrated. As a result, much of Catholic church services and education and record keeping was forced underground, to operate only under extreme secrecy. The religion and culture were kept alive by secret open-air masses and illegal outdoor schools, known as 'hedge' schools. All Irish culture, music and education was banned. By the time of the census of 1841 the Irish were impoverished, landless and leaderless by the eve of the famine.
Professor Lecky a British Protestant and ardent British sympathizer, said in his "History of Ireland in the 18th Century" that the object of the Penal Laws was threefold:
"To deprive Catholics of all civil life; to reduce them to a condition of extreme, brutal ignorance; and, to disassociate them from the soil.:
Lecky said, "He might with absolute justice, substitute Irish for Catholic, "and added a fourth objective: "To expatriate the race." Most scholars agree that the Penal Laws helped set the stage for the injustices that occurred during The Great Famine and fueled the fires of racism that were directed against the Irish by the British. Lecky outlined the Penal Laws as follows:
The Catholic Church forbidden to keep church registers.
The Irish Catholic was forbidden the exercise of his religion.
He was forbidden to receive education.
He was forbidden to enter a profession.
He was forbidden to hold public office.
He was forbidden to engage in trade or commerce.
He was forbidden to live in a corporate town or within five miles thereof.
He was forbidden to own a horse of greater value than five pounds.
He was forbidden to own land.
He was forbidden to lease land.
He was forbidden to accept a mortgage on land in security for a loan.
He was forbidden to vote.
He was forbidden to keep any arms for his protection.
He was forbidden to hold a life annuity.
He was forbidden to buy land from a Protestant.
He was forbidden to receive a gift of land from a Protestant.
He was forbidden to inherit land from a Protestant.
He was forbidden to inherit anything from a Protestant.
He was forbidden to rent any land that was worth more than 30 shillings a year.
He was forbidden to reap from his land any profit exceeding a third of the rent.
He could not be guardian to a child.
He could not, when dying, leave his infant children under Catholic guardianship.
He could not attend Catholic worship.
He was compelled by law to attend Protestant worship.
He could not himself educate his child.
He could not send his child to a Catholic teacher.
He could not employ a Catholic teacher to come to his child.
He could not send his child abroad to receive education.
* From: MacManus " the story of the Irish Race" 1921.Devin-Adair Publishing Co., New York.