Merriam-Webster Collegiate Dictionary - concentrate

 I. verb  (-trated; -trating)  Etymology: com- + Latin centrum center  Date: 1641  transitive verb  1.  a. to bring or direct toward a common center or objective ; focus ~ one's efforts  b. to gather into one body, mass, or force power was ~d in a few able hands  c. to accumulate (a toxic substance) in bodily tissues fish ~ mercury  2.  a. to make less dilute ~ syrup  b. to express or exhibit in condensed form  intransitive verb  1. to draw toward or meet in a common center  2. gather, collect  3. to focus one's powers, efforts, or attention ~ on a problem  • ~dly adverb  • concentrative adjective  II. noun  Date: 1883  1. something ~d: as  a. a mineral-rich product obtained after an initial processing of ore  b. a food reduced in bulk by elimination of fluid orange juice ~  2. a feedstuff (as grains) relatively rich in digestible nutrients — compare fiber