Intensive  adj. 1 thorough, vigorous; directed to a single point, area, or subject (intensive study; intensive bombardment). 2 of or relating to intensity. 3 serving to increase production in relation to costs (intensive farming). 4 (usu. In comb.) Econ. Making much use of (labour-intensive). 5 (of an adjective, adverb, etc.) Expressing intensity, e.g. Really in my feet are really cold.  intensively adv. Intensiveness n.