a central point, as of attraction, attention, or activity

The need to prevent a nuclear war became the focus of all diplomatic efforts.

Physics . a point at which rays of light, heat, or other radiation, meet after being refracted or reflected.

Optics .

the focal point of a lens.

the focal length of a lens.

the clear and sharply defined condition of an image.

the position of a viewed object or the adjustment of an optical device necessary to produce a clear image

in focus; out of focus.

Geometry . (of a conic section) a point having the property that the distances from any point on a curve to it and to a fixed line have a constant ratio for all points on the curve.

Geology . the point of origin of an earthquake.

Pathology . the primary center from which a disease develops or in which it localizes.

to bring to a focus or into focus

to focus the lens of a camera.

to concentrate

to focus one's thoughts.

to become focused.

verb

ignore , neglect

noun

bull’s eye , center , core , cynosure , focal point , headquarters * , heart , hub , limelight * , locus , meeting place , nerve center * , point of convergence , polestar , seat , spotlight , target , headquarters , bottom , quick , root

verb

adjust , attract , bring out , center , centralize , concenter , concentrate , convene , converge , direct , fasten , fix , fixate , get detail , home in , home in on , hone in , join , key on , knuckle down * , meet , move in , pinpoint , pour it on , put , rivet , sharpen , spotlight * , sweat * , zero in * , zoom in , channel , focalize , address , bend , buckle down , dedicate , devote , give , turn , core , fireplace , hearth , point , spotlight , train