Concentration

n.	1.	The act or process of concentrating; the process of becoming concentrated, or the state of being concentrated; concentration. Concentration of the lunar beams. - Boyle. Intense concetration of thought. - Sir J. Herschel.
	2.	The act or process of reducing the volume of a liquid, as by evaporation. The acid acquires a higher degree of concentration. - Knight.
	3.	(Metal.) The act or process of removing the dress of ore and of reducing the valuable part to smaller compass, as by currents of air or water.

Noun	1.	concentration - the strength of a solution; number of molecules of a substance in a given volume (expressed as moles/cubic meter)
	2.	concentration - the spatial property of being crowded together Synonyms: compactness, denseness, density Antonyms: dispersion, distribution - the spatial property of being scattered about over an area or volume
	3.	concentration - strengthening the concentration (as of a solute in a mixture) by removing extraneous material Antonyms: dilution - weakening (reducing the concentration) by the addition of water or a thinner
	4.	concentration - increase in density
	5.	concentration - complete attention; intense mental effort Synonyms: engrossment, immersion, absorption
	6.	concentration - bringing together military forces
	7.	concentration - great and constant diligence and attention Synonyms: assiduity, assiduousness

abbreviation, absorbed attention, absorption, abstraction, accelerando, acceleration, advertence, advertency, agglutination, aggravation, alertness, application, approach, ardor, assiduity, assiduousness, astriction, astringency, asymptote, attention, attention span, attentiveness, awareness, beefing-up, blowing up, blowup, bottleneck, brown study, bulldog tenacity, care, centering, centralism, centralization, cervix, circumscription, close study, clumping, clustering, coarctation, collision course, compactedness, compaction, compression, compressure, concentralization, concentrate, concourse, concretion, concurrence, condensation, confluence, conflux, congress, consciousness, consideration, consolidation, constancy, constriction, constringency, contemplation, contemplativeness, contraction, contracture, convergence, converging, crossing, curtailment, debate, decoction, decrease, deep study, deep thought, deepening, deliberation, densification, diligence, diminuendo, distillate, distillation, dogged perseverance, doggedness, ear, earnestness, elixir, endurance, energeticalness, energy, engagement, engrossment, enhancement, enthrallment, essence, exacerbation, exaggeration, explosion, expression, extract, extraction, fervor, fidelity, firmness, firmness of mind, fixedness, flintiness, focalization, focus, focusing, funnel, hardening, heating-up, heed, heedfulness, heightening, hourglass, hourglass figure, hub, immersion, indefatigability, industriousness, industry, inflexibility, information explosion, infusion, insistence, insistency, intensification, intentiveness, intentness, involvement, isthmus, knitting, laboriousness, loyalty, magnification, meditation, meeting, melancholy, mindfulness, monomania, musing, mutual approach, narrow place, narrowing, narrowing gap, neck, note, notice, observance, observation, obsession, obstinacy, patience, patience of Job, pensiveness, permanence, perseverance, persistence, persistency, pertinaciousness, pertinacity, pickup, plodding, plugging, pooling, population explosion, preoccupation, pressing, profound thought, puckering, purification, pursing, quintessence, radius, rapt attention, redoubling, reduction, refinement, reflectiveness, regard, regardfulness, reinforcement, relentlessness, remark, rendering, rendition, resolution, respect, reverie, rigidity, sedulity, sedulousness, settledness, shortening, single-mindedness, singleness of purpose, slogging, soaking, solidification, speculativeness, speedup, spirit, spokes, squeezing, stability, stamina, staunchness, staying power, steadfastness, steadiness, steeliness, steeping, step-up, stick-to-itiveness, stranglement, strangulation, strengthening, strenuousness, striction, stricture, stubbornness, studiousness, study, submersion, systole, tangent, tenaciousness, tenacity, thought, thoughtfulness, tightening, tirelessness, trueness, unremittingness, unsparingness, unswerving attention, unyieldingness, vehemence, wasp waist, wistfulness, wrinkling, zealousness