focus (Noun) — The concentration of attention or energy on something. ex. "the focus of activity shifted to molecular biology"
focus (Noun) — Maximum clarity or distinctness of an image rendered by an optical system. ex. "in focus" ex. "out of focus"
focus (Noun) — Maximum clarity or distinctness of an idea. ex. "the controversy brought clearly into focus an important difference of opinion"
focus (Noun) — A central point or locus of an infection in an organism. ex. "the focus of infection"
focus (Noun) — Special emphasis attached to something. ex. "the focus was more on accuracy than on speed"
focus (Noun) — A point of convergence of light (or other radiation) or a point from which it diverges.
focus (Noun) — A fixed reference point on the concave side of a conic section.
focus (Noun) — (computing) the active element in a user interface, typically where user input will appear on screen. ex. "when you click a text box, it gets the input focus"
focus (Verb) — Direct one's attention on something. ex. "Please focus on your studies and not on your hobbies"
focus (Verb) — Cause to converge on or toward a central point. ex. "Focus the light on this image"
focus (Verb) — Bring into focus or alignment; to converge or cause to converge; of ideas or emotions.
focus (Verb) — Become focussed or come into focus. ex. "The light focused"
focus (Verb) — Put (an image) into focus. ex. "Please focus the image; we cannot enjoy the movie"