O’Donnell said the words’ meanings had been "hijacked" by the secular environment, which pushes them ever further away from actual believers.
"We’ve lost Christmas, just like we lost Easter, and should abandon the word completely," O’Donnell told the Belfast Telegraph. "We need to let it go, it’s already been hijacked and we just need to recognize and accept that."
O’Donnell said he has no intention of disparaging non-believers, adding they also have a right to engage in Christmas celebrations the way they understand it. "I am simply asking that space be preserved for believers for whom Christmas has nothing to do with Santa and reindeer."
"My religious experience of true Christmas, like so many others, is very deep and real – like the air I breathe. But non-believers deserve and need their celebration too, it’s an essential human dynamic and we all need that in the toughness of life."
He suggests the reason why the names of the festivities became secularized lies in their excessive commercialization.
"I’m just trying to rescue the reality of Christmas for believers by giving up 'Christmas' and replacing it with another word."
The priest’s call came after rightwing activists had lashed out at Greggs bakery in Britain as they replaced baby Jesus with a sausage in a Holy nativity scene.
O’Donnell claimed that unless Catholicism seriously takes into account the reality of what the word Christmas has come to mean, "secularization and modern life will continue to launder the church".