- Main Entry:
- 1fo·cus
- Pronunciation:
-
\ˈfō-kəs\
- Function:
- noun
- Inflected Form(s):
- plural fo·ci \ˈfō-ˌsī also -ˌkī\ also fo·cus·es
- Etymology:
- New Latin, from Latin, hearth
- Date:
- 1644
1 a: a point at which rays (as of light, heat, or sound) converge or from which they diverge or appear to diverge; specifically : the point where the geometrical lines or their prolongations conforming to the rays diverging from or converging toward another point intersect and give rise to an image after reflection by a mirror or refraction by a lens or optical system b: a point of convergence of a beam of particles (as electrons)2 a: focal length b: adjustment for distinct vision; also : the area that may be seen distinctly or resolved into a clear image c: a state or condition permitting clear perception or understanding <tried to bring the issues into focus> d: direction 6c <the team lost focus>3: one of the fixed points that with the corresponding directrix defines a conic section4: a localized area of disease or the chief site of a generalized disease or infection5 a: a center of activity, attraction, or attention <the focus of the meeting was drug abuse> b: a point of concentration6: the place of origin of an earthquake or moonquake7: directed attention : emphasis
—
fo·cus·less \-ləs\ adjective —
in focus : having or giving the proper sharpness of outline due to good focusing
—
out of focus : not in focus
