Search results for 'focus':

focus noun (focuses or foci) 1 the point at which rays of light or sound waves converge or appear to diverge. 2 optics focal point 1. 3 a the condition in which an image is sharp • The picture is in focus; b the state of an instrument producing this image • The telescope is in focus • These binoculars are out of focus. 4 geol in seismology: the location of the centre of an earthquake, where the subterranean fracture takes place and from which the elastic waves radiate outward. See also epicentre. 5 a centre of interest or attention. 6 special attention paid to something • a shift of focus. 7 pathol the main site of an infection. 8 geom a point associated with a conic section where the distance between it and any point on the curve is a fixed ratio (the eccentricity 4) to the distance between that point and a line (the directrix). verb (focused, focusing; focussed, focussing) 1 tr & intr to bring or be brought into focus; to meet or make something meet or converge at a focus. 2 to adjust the thickness of the lens of (the eye) or to move the lens of (an optical instrument) so as to obtain the sharpest possible image of a particular object. 3 to cause (electron beams) to converge or diverge by varying the voltage or current that controls the magnetic or electric fields through which they pass. 4 (often focus something on something) tr & intr to concentrate (one's attention, etc) on it • focused her energies on the problem • focused on the problem.
ETYMOLOGY: 17c: Latin, meaning 'hearth or fireplace'; probably referring to the 'burning point of a lens or mirror'.

focus noun (focuses or foci) 1 the point at which rays of light or sound waves converge or appear to diverge. 2 optics focal point 1. 3 a the condition in which an image is sharp • The picture is in focus; b the state of an instrument producing this image • The telescope is in focus • These binoculars are out of focus. 4 geol in seismology: the location of the centre of an earthquake, where the subterranean fracture takes place and from which the elastic waves radiate outward. See also epicentre. 5 a centre of interest or attention. 6 special attention paid to something • a shift of focus. 7 pathol the main site of an infection. 8 geom a point associated with a conic section where the distance between it and any point on the curve is a fixed ratio (the eccentricity 4) to the distance between that point and a line (the directrix). verb (focused, focusing; focussed, focussing) 1 tr & intr to bring or be brought into focus; to meet or make something meet or converge at a focus. 2 to adjust the thickness of the lens of (the eye) or to move the lens of (an optical instrument) so as to obtain the sharpest possible image of a particular object. 3 to cause (electron beams) to converge or diverge by varying the voltage or current that controls the magnetic or electric fields through which they pass. 4 (often focus something on something) tr & intr to concentrate (one's attention, etc) on it • focused her energies on the problem • focused on the problem.
ETYMOLOGY: 17c: Latin, meaning 'hearth or fireplace'; probably referring to the 'burning point of a lens or mirror'.

focus noun (focuses or foci) 1 the point at which rays of light or sound waves converge or appear to diverge. 2 optics focal point 1. 3 a the condition in which an image is sharp • The picture is in focus; b the state of an instrument producing this image • The telescope is in focus • These binoculars are out of focus. 4 geol in seismology: the location of the centre of an earthquake, where the subterranean fracture takes place and from which the elastic waves radiate outward. See also epicentre. 5 a centre of interest or attention. 6 special attention paid to something • a shift of focus. 7 pathol the main site of an infection. 8 geom a point associated with a conic section where the distance between it and any point on the curve is a fixed ratio (the eccentricity 4) to the distance between that point and a line (the directrix). verb (focused, focusing; focussed, focussing) 1 tr & intr to bring or be brought into focus; to meet or make something meet or converge at a focus. 2 to adjust the thickness of the lens of (the eye) or to move the lens of (an optical instrument) so as to obtain the sharpest possible image of a particular object. 3 to cause (electron beams) to converge or diverge by varying the voltage or current that controls the magnetic or electric fields through which they pass. 4 (often focus something on something) tr & intr to concentrate (one's attention, etc) on it • focused her energies on the problem • focused on the problem.
ETYMOLOGY: 17c: Latin, meaning 'hearth or fireplace'; probably referring to the 'burning point of a lens or mirror'.