1. (verb) to keep steadily on course, head straight.
Ka tīmata i te taha hauraro o te tino wahapū o Herekino, ka rere atu i reira, mārō tonu ki te tihi o Maungataniwha, ka mārō atu i reira i runga i te kahiwi maunga tauārai o ngā hikuwai o ngā awa o Hokianga, ā tae noa ki te mātāpuna o te awa o Waimā (TKM.MM 5/2/1862:29). / It commences at the northern side of the mouth of Herekino, thence by a straight line to the summit of Maungataniwha, thence following the ridges forming the watershed of the Hokianga River right to the headwaters of the Waimā River.
2. (modifier) stiff, hard, solid, unyielding, determined, firm.
Kaua he kai mārō e hoatu. / Don't give her solid food.
3. (noun) measurement made with the arms extended roughly equivalent to a fathom (6 ft or 1.8 m).
Ka tukua te taura whakatātūtū ki raro, ka kitea te hōhonu e waru tekau mā rima mārō i taua wāhi (TWMNT 14/7/1874:172). / When the measuring line was passed down, the depth was seen to be eighty-five fathoms at that place.
(Te Kōhure Textbook (Ed. 2): 114;)