A Quick and Simple Dictionary

focus

1. Noun.  (countable, optics) a point at which reflected or refracted rays of light converge.
2. Noun.  (countable, geometry) a point of a conic at which rays reflected from a curve or surface converge.
3. Noun.  (uncountable, photography) The fact of the convergence of light on the photographic medium.
4. Noun.  (uncountable, photography) The quality of the convergence of light on the photographic medium.
5. Noun.  (uncountable) concentration of attention.
6. Noun.  (countable) the exact point of where an earthquake occurs, in three dimensions.
7. Noun.  (computing, GUI) The indicator of the currently active element in a user interface.
8. Noun.  (linguistics) The most important word or phrase in a sentence or passage, or the one that imparts information.
9. Verb.  (transitive) To cause (rays of light, etc) to converge at a single point.
10. Verb.  (transitive) To adjust (a lens, an optical instrument) in order to position an image with respect to the focal plane.
11. Verb.  (transitive, followed by '''on''' or '''upon''') To concentrate one's attention.
12. Verb.  (transitive) To make (a liquid) less diluted.
13. Verb.  (intransitive) To concentrate one’s attention.