The colloquial phrase, which is used almost exclusively in New Zealand politics, is among several new words the dictionary has included in its latest update.
It defines a waka jumper as a member of Parliament who moves from one political party to another during a parliamentary term.
The dictionary says that the phrase has been in use since 1999.
"Waka jumping (1999) is the name for this practice of party switching, and a waka jumper (1999) is a member of Parliament who engages in it."
The most recent waka jumping legislation passed in 2018.
Other New Zealand words added to the dictionary included:
- 'tikanga' - "a custom, norm, value, or principle regulating the behaviour and practices of a particular community"
- 'tikanga Māori' - "the body of such customs, norms, values, or principles regulating the behaviour and practices of the Māori people specifically"
- 'kapa haka' - "a traditional Māori performing arts group"
- 'mahi' - "used in Māori contexts to mean work, activity, occupation, or employment"
- 'chilly bin' - "portable insulated container designed to keep food or drinks cool"
- 'ditch' - the Tasman Sea.
- 'Aotearoan' - "a native or inhabitant of Aotearoa (New Zealand)"
Other new regional words and phrases that the dictionary has added this round include the Welsh interjection of disgust 'ych a fi' and 'towel' as slang for the Guyanese one-thousand-dollar bill.
The one word that's surprising experts
There has been an increase in the number of te reo Māori words being added to the dictionary, with experts saying it's a sign of the times as more Māori and non-Māori use certain words.
University of Auckland linguist Dr Peter Keegan said the addition of the words did not surprise him, given they were used often in the media and people in New Zealand.
The one that may have caught some by surprise was 'Aotearoan'.
Keegan said people should not be surprised terms like 'kapa haka' have been added as they are well represented in media.
Victoria University Emeritus professor of linguistics John Macalister was Oxford's go-to consultant on New Zealand English.
The university updated its dictionary about four times a year, he said.
"It's a regular process, but it is a big event because what it is doing is it's capturing the changing nature of New Zealand society through the language that's used.
"And it's also capturing the distinctive nature of New Zealand society both in historical and contemporary terms."
Māori Language Commission chief executive Ngahiwi Apanui said the inclusion of Māori words was great news.
"It recognises how te reo Māori has become part of the New Zealand vernacular... That's something for us to celebrate in Māori Language Week."
Aucklander Richard agreed. "I think [it's] tremendous that our reo is getting included in the Oxford dictionary... They're part of the reo of our country."
Another resident, Adrian, said it was nice to see New Zealanders embrace te reo.
"I've always thought people should embrace it, personally I didn't really embrace my Māori side until my early teens," he said.
"It's been more of an enriching experience than anything else and I don't see why people wouldn't take that opportunity."
But one word stuck out.
"I don't mind any of them apart from 'Aotearoan,' because it's kind of bastardising te reo. It's combining a te reo word with... I guess an English ending on it," he said.
"As part Māori, it doesn't feel quite right."
Apanui felt the same way.
"Yeah, I'm not particularly keen on that one, because it's not consistent with our orthographic conventions.
"But people are going to use the language like that and you can't stop them. I'd prefer something like 'tangata Aotearoa'."
Macalister said enough people called themselves Aotearoans to justify including it in the dictionary, but he did not think the term would replace New Zealander or Kiwi.
"If I was betting person, I would bet that it's unlikely to be widely adopted," he admitted.
