Mining company Adani has changed its name to a Latin word that means “crooked”, “deformed”, “mercenary or assassin”, after mistakenly thinking that it meant “brave”.

The controversial mining group, which is responsible for the Carmichael coalmine in central Queensland, announced on Thursday it would change the name of its Australian operation to “Bravus”, a word identified by chief executive David Boshoff as the medieval Latin word for “courageous”.

Boshoff told the Australian Financial Review it was a good fit because the company “took a lot of courage to get where we are and we will stand up for what we believe in”.

However, multiple Latin experts have pointed out that “bravus” does not mean “brave” and is more accurately translated as “crooked” or “mercenary”.

Dr Christopher Bishop, from the Australian National University’s centre of classical studies, said “bravus” did not mean “brave” in either classical or medieval Latin.

“They are wrong,” he told Guardian Australia. “It would have to be something like ‘fortis’, for brave, if you are going for your classical. You know, something like ‘fortuna favet fortibus – fortune favours the brave’. That’s a schoolboy thing – everyone knows that.”

Dr Juanita Feros Ruys from the University of Sydney agreed.

“The most common Latin term for the concept of ‘brave’ would be ‘fortis’ (from where we derive ‘fortify’, ‘fortitude’) and that would appear to be the case for both classical and medieval Latin, for each of which there are many examples,” she said.

Bishop said medieval Latin was often difficult to translate, but most translations of “bravus” would, unfortunately for Adani, have negative connotations.

“It is sort of a Monty Python-Latin,” he told Guardian Australia. “It is that classic joke where you chuck an ‘-us’ on to the end of anything and call it Latin.”

Bishop said the closest relative to “bravus” was the medieval Latin word “bravo” – a noun meaning a “mercenary”, “assassin” or “sword for hire”.

“As far as I know, it [bravus] is an unattested medieval word,” he said.

“You have ‘bravo’ – meaning a mercenary, a sword for hire, a tough guy. Which is probably not what they want to associate with. The closest Adani could get is it could have meant ‘boldness’. But it is a pretty militant boldness.”

Prof Tim Parkin from the University of Melbourne said he found an entry for “bravus” in a dictionary of medieval Latin.

“It tends to be used of someone who is villainous,” he said. “A crook, or a bandit, or a cut-throat.”

According to an article from the Oxford University Press, “bravus” could be derived from either the classical Latin word “pravus” – meaning crooked, bad or depraved – or the classical Latin word “barbarus” – meaning barbaric, foreign or uncouth.

Bishop said: “Even if it is not ‘barbarus’, it could be a mispronunciation of ‘pravus’. Ps, Bs and Fs always get mixed up – it could literally be ‘pravus’, which means ‘bad, crooked, depraved’. Maybe it is ‘barbarus’ plus ‘pravus’ – meaning a depraved barbarian.”

Initially named after its founder, the Indian billionaire Gautam Adani, the Adani Group launched the Carmichael coal mine project in 2014.

A spokeswoman for Adani/Bravus said the new name was “derived from the words ‘brave’ or ‘bold’.”

“It includes the ‘us’ suffix, highlighting the inclusive nature of us the company, us the employees and us the community. It references the fact we are an Australian company by having the letters ‘AUS’ in the name. It signifies that we are proud to be an Australian company that is part of the North Queensland community.”

Speaking to the AFR, Boshoff denied the name was being changed because it was “toxic”. “If [we were] motivated by that it would have made sense to change our name 18 months ago or earlier,” he said.

The Adani name change comes after the company quietly rebranded its Abbot Point coal terminal to the North Queensland Export Terminal earlier this year.

In 2015, the operator of the Manus Island and Nauru detention centres, Transfield Services, changed its name to Broadspectrum. In 2009, the US private military company Blackwater changed its name to Xe after its contractors killed civilians in Iraq.

More recently, tech company Google rebranded its parent company as Alphabet, WeWork rebranded to The We Company after large losses, and Facebook rebranded to FACEBOOK to “add a sense of optimism” in November last year.

Parkin told Guardian Australia that Adani should have “consulted a classics department rather than gone to Google translate”.

“It reminds me of one of my brothers wanting a name for his boat, and I came up with some wonderful classics names for it. And, in the end, I think he went for something like ‘boatus’.”