1. The strength of a solution; number of molecules of a substance in a given volume
   "The concentration of the acid was too high for safe handling"
    
2. Complete attention; intense mental effort
   "His concentration while solving the puzzle was impressive";
   - engrossment, absorption, immersion
    
3. Great and constant diligence and attention
   "The student's concentration in his studies resulted in top grades";
   - assiduity, assiduousness
    
4. Strengthening the concentration (as of a solute in a mixture) by removing diluting material
   "The concentration of the juice by evaporation enhanced its flavour"
    
5. The spatial property of being crowded together
   "The high concentration of people in the city centre created traffic problems";
   - density, denseness, tightness, compactness
    
6. Increase in density
   "The concentration of pollutants in the air reached dangerous levels"
    
7. Bringing together military forces
   "The concentration of troops near the border raised tensions"

Derived forms: concentrations

Type of: assemblage, assembly, attention, diligence, gathering, increase, industriousness, industry, property, spacing, spatial arrangement, strengthening

Antonym: dilution

Encyclopedia: Concentration