1 centre, concentration, focal point, heart, core, target, convergence, hub, nave; cynosure:
Why should Anita always be the focus of attention?
2 in focus. clear, distinct, well- or sharply defined:
With the telescope in focus, you feel as if you can almost touch the distant shore.
3 out of focus. unclear, indistinct, blurred, blurry, fuzzy, woolly:
The photos are so out of focus that I can't tell who's who.
4 concentrate, centre, converge, meet, pinpoint, spotlight; bring into focus; Colloq zero in:
Without distractions, we can focus on the problem at hand.