FOCUS

I. noun (plural foci; also ~es) Etymology: New Latin, from Latin, hearth Date: 1644 1. a point at which rays (as of light, heat, or sound) converge or from which they diverge or appear to diverge, a point of convergence of a beam of particles (as electrons), 2. focal length , adjustment for distinct vision, a state or condition permitting clear perception or understanding , direction 6c , one of the fixed points that with the corresponding directrix defines a conic section, a localized area of disease or the chief site of a generalized disease or infection, 5. a center of activity, attraction, or attention , a point of concentration, the place of origin of an earthquake or moonquake, directed attention ; emphasis , ~less adjective II. verb (~ed; also ~sed; ~ing; also ~sing) Date: 1775 transitive verb 1. to bring into ~, to adjust the ~ of (as the eye or a lens), to cause to be concentrated , to bring (as light rays) to a ~ ; concentrate , intransitive verb to come to a ~ ; converge , to adjust one's eye or a camera to a particular range, to concentrate attention or effort, ~able adjective ~er noun