manuka (?m??nu?k?) n (Plants) a New Zealand myrtaceous tree, Leptospermum scoparium, with strong elastic wood and aromatic leaves. Also called: red tea tree or kahikatoa Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014