From roro(“brain”) + hiko(“lightning, electricity”), literally “electric brain”. Compare Hawaiianlolouila and Chinese電腦 / 电脑(diànnǎo) for similar constructions.
John C. Moorfield (2011), “rorohiko”, in Te Aka: Māori–English, English–Māori Dictionary and Index, 3rd edition, Longman/Pearson Education New Zealand, →ISBN