The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

focusing \focusing\, focussing \focussing\n.
   1. the concentration of attention or energy on something.

   Syn: focus, focussing.
        [WordNet 1.5]

   2. the act of bringing into focus.

   Syn: focalization, focalisation.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

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, focusing,
         focussing, focal point, direction, centering]
    2: the act of bringing into focus [syn: focalization,
       focalisation, focusing]