Source : Webster's Revised Unabridged Dictionary (1913)

Focus \Fo"cus\, v. t. [imp. & p. p. {Focused}; p. pr. & vb. n.
   {Focusing}.]
   To bring to a focus; to focalize; as, to focus a camera. --R.
   Hunt.

Source : WordNet®

focusing
     n 1: the concentration of attention or energy on something; "the
          focus of activity shifted to molecular biology"; "he had
          no direction in his life" [syn: {focus}, {focussing}, {direction},
           {centering}]
     2: the act of bringing into focus [syn: {focalization}, {focalisation}]