—v.t. 1. to bring or draw to a common center or point of union; converge; direct toward one point; focus: to concentrate one's attention on a problem; to concentrate the rays of the sun with a lens. 2. to put or bring into a single place, group, etc.: The nation's wealth had been concentrated in a few families. 3. to intensify; make denser, stronger, or purer, esp. by the removal or reduction of liquid: to concentrate fruit juice; to concentrate a sauce by boiling it down. 4. Mining.to separate (metal or ore) from rock, sand, etc., so as to improve the quality of the valuable portion.
—v.i. 1. to bring all efforts, faculties, activities, etc., to bear on one thing or activity (often fol. by on or upon): to concentrate on solving a problem. 2. to come to or toward a common center; converge; collect: The population concentrated in one part of the city. 3. to become more intense, stronger, or purer.
—n. a concentrated form of something; a product of concentration: a juice concentrate.