concentration concentration /ˌkɑːnsənˈtreɪʃən/

noun

1. () The strength of a solution; number of molecules of a substance in a given volume  ( concentration )
   the strength of a solution; number of molecules of a substance in a given volume
     The concentration of chemicals in the solution needed to be measured accurately.
   The concentration of chemicals in the solution needed to be measured accurately.
   
2. () The spatial property of being crowded together  ( compactness , denseness , tightness , concentration , density )
   the spatial property of being crowded together
   
3. () Strengthening the concentration (as of a solute in a mixture) by removing diluting material  ( concentration )
   strengthening the concentration (as of a solute in a mixture) by removing diluting material
   
4. () Complete attention; intense mental effort  ( absorption , engrossment , immersion , concentration )
   complete attention; intense mental effort
   
5. () Increase in density  ( concentration )
   increase in density
   
6. () Bringing together military forces  ( concentration )
   bringing together military forces
   
7. Great and constant diligence and attention  ( assiduousness , concentration , assiduity )
   great and constant diligence and attention