1. (v. t.) To bring to, or direct toward, a common center; to unite more closely; to gather into one body, mass, or force; to fix; as, to concentrate rays of light into a focus; to concentrate the attention.

2. (v. t.) To increase the strength and diminish the bulk of, as of a liquid or an ore; to intensify, by getting rid of useless material; to condense; as, to concentrate acid by evaporation; to concentrate by washing; -- opposed to dilute.

3. (v. i.) To approach or meet in a common center; to consolidate; as, population tends to concentrate in cities.

abbreviate accelerate aggravate approach assemble attend closely to attend to business be alert be obsessed with beef up blow up bring into focus bring together center centralize circumscribe close close in close up close with cluster coarct collect come together compact complicate compress concenter concentralize concentrate on concentrate the mind concentrate upon concentrated concentration condense congest congregate consolidate constant constrict constringe contract converge cram cramp crowd curtail decoct decoction decrease deepen densen densify direct distill distillate distillation double draw draw in draw together elixir enhance essence essentialize establish exacerbate exaggerate exclusive express extract extraction fall in with firm fix fix on fixate fixed focalize focus focus on funnel gather give heed group heap heat up heighten hop up hot up infuse infusion integrate intensify intersect jam jazz up key up knit look lively look out look sharp magnify make complex mass meet melt down miss nothing narrow narrow the gap nip pay attention pay heed pile pinch press press out pucker pucker up purification purse put quintessence ram down ramify redouble reduce refine refinement reinforce render rivet run together scrutinize set settle sharpen shorten shrink soak solidify soup up spirit squeeze steadfast steady steep step up strangle strangulate strengthen study take care take heed taper think triple undistracted undivided unfaltering unite unremitting unwavering watch out whet wring wring out wrinkle