1. (noun) ridge pole (of a house), ridge-beam (of a house), main theme, subject of a sentence.
Ko Tākitimu te whare pai ngā waihanga, engari nō taku kitenga i a Porourangi heoi anō kua ngaro ōku mahara ki a Takitimu, kua riro katoa kua whaiāipo ki a Porourangi; i te tamatāne o te āhua, o te tū o te whare; i te rite, i te ātanga, o ngā whakairo, o ngā pou, o ngā pakitara, o te tungaroa, me te whatitoka, me te roro, me te matapihi, me ngā arapaki, kāore he rite i i kitea e ahau i te motu katoa nei, hāunga hoki ngā tuhituhi o ngā heke me te tāhū. (TP 1/7/1902:6). / Tākitimu was built beautifully, but when I saw Porourangi my thoughts about Tākitimu were forgotten and I fell in love with Porourangi; the youthful masculinity of the house's appearance and structure; the architecture and beauty of the carvings, posts, walls, the back wall and the door, verandah, window and the ornamental lattice-work, and not to mention the paintings of the rafters and the ridgepole.
2. (noun) direct line of ancestry through the senior line.
Ko ēnei tāngata, ko Tuamatua rāua ko Uruika, ko rāua te tāhū nui o Te Hekengarangi, te tino kāwai ariki: ko rāua te tāhū iho, tae iho ki ngā uri (W 1971:360). / These two people, Tuamatua and Uruika, are the direct line of ancestry of Te Hekengarangi, the senior line: they are the direct line down to the descendants.
3. (noun) subject of a sentence (grammar).
I te rerenga 'Kei te kai rātou', ko te kupu 'rātou' te tāhū. I te rerenga 'E ngongoro ana te ihu', ko 'te ihu' te tāhū (PK 2008:810). / In the sentence 'Kei te kai rātou', the word 'rātou' is the subject. In the sentence 'E ngongoro ana te ihu', the subject is 'te ihu'.
4. (noun) plot (drama).
Kātahi te tāhū whīwhiwhi, me whakamāmā pea (RMR 2017). / What a complicated plot. Perhaps it should be simplified.