(noun) with deep affection - often used in signing off letters to friends. More correctly, it should be written as two words, aroha nui. See aroha, nui.
aroha: 1. (verb) (-ina,-tia) to love, feel pity, feel concern for, feel compassion, empathise. Aroha ana ngā tangi a ō mātou wāhine (HM 4/2009 wh1).The crying of our women was heart-rending.
2. (noun) affection, sympathy, charity, compassion, love, empathy. Tērā tātau e rongo kei te tuwha haere a Henare i ana hipi, i ana kau ki a Ngāti Porou, hei kaihaukai māna ki tōna iwi, he nui nō tōna aroha! (Pipi 7/1900 wh8). We have heard that, because of his charity, Henare is distributing his sheep and cows to Ngāti Porou as feasts for his people. See also aroha nui.
nui: 1. (stative) be large, big, many, plentiful, numerous, great, abundant, ample, superior, of high rank, important. He nui hoki ngā taika kei te ngahere tata atu ki taua kāinga (TTT 1/6/1923 wh3).There are also many tigers in the bush near that village. See also aroha nui.
2. (noun) size, quantity, vastness, greatness, importance, amount, abundance, plenty, rank
Te Aka Māori-English, English-Māori Dictionary and Index
Edition: 1st, Pages: 376, Edition publication date: 2005
Publisher: Longman/Pearson Education New Zealand
Aroha, also a popular female name.