focussing

1. (followed by on or upon) To concentrate one's attention.

   I have to focus on my work.

2. To cause (rays of light, etc) to converge at a single point.
3. To adjust (a lens, an optical instrument) in order to position an image with respect to the focal plane.

   You'll need to focus the microscope carefully in order to capture the full detail of this surface.

4. To concentrate one’s attention.

   If you're going to beat your competitors, you need to focus.

5. To transfer the input focus to (a visual element), so that it receives subsequent input.

   The text box won't receive the user's keystrokes unless you explicitly focus it.

noun

The action of the verb to focus.

adjective

Used for or pertaining to focusing.