The species name, eueu, comes from the Khwedam word meaning 'big fish', as most of the strandings of these whales come from Khoisan territories in South Africa.

The common name honours Māori whale expert Ramari Stewart.

However, studies of the Indian Ocean beaked whales found them to be genetically distinct from True's beaked whale, having diverged in the early Pleistocene, and also found them to have a much wider range throughout the Southern Hemisphere.

[3] The holotype is a 5-metre-long (16 ft) pregnant female who washed ashore in 2011 on Waiatoto Spit, south of Haast, New Zealand.

The complete skeleton of her and her foetus are held in the Museum of New Zealand Te Papa Tongarewa in Wellington, and a tissue sample is in the New Zealand Cetacean Tissue Archive in Auckland.