From Proto-Polynesian*tuqu-taki (“to join together” – compare with Hawaiiankūkaʻi “rope fastening fish nets together”, Tongantuʻutaki “to join or tie together”, Samoantutaʻi “to join or knot together [of ropes]”), reanalyzable as tū + taki.[1][2] Sense “to shut an enclosure, to block, to lock” is influenced by a homograph of taki “to stick or plant in the ground, to stake” and its reduplicate form takitaki “fence, palisade”.
Williams, Herbert William (1917) “tūtaki”, in A Dictionary of the Maori Language, pages 541-2
“tūtaki” in John C. Moorfield, Te Aka: Maori–English, English–Maori Dictionary and Index, 3rd edition, Longman/Pearson Education New Zealand, 2011, →ISBN.