[v] put into focus; as of an image on a screen; "Please focus the image; we cannot enjoy the movie"
[v] become sharp or sharper; "The debate sharpened"
[v] make sharp or sharper; "We had to sharpen our arguments"
[v] make more acute; as of one's senses; "This drug will sharpen your vision"
[v] give a point to; "The candles are tapered"
[v] raise the pitch of (musical notes)
[v] make sharp or sharper; "sharpen the knives"
[v] make sharp or sharper of images and sounds