focus has 17 distinct synonyms spread across 8 of its 12 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is blur.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the concentration of attention or energy on something
“the focus of activity shifted to molecular biology”
maximum clarity or distinctness of an image rendered by an optical system
“in focus”
maximum clarity or distinctness of an idea
“the controversy brought clearly into focus an important difference of opinion”
a central point or locus of an infection in an organism
“the focus of infection”
a point of convergence of light (or other radiation) or a point from which it diverges
a fixed reference point on the concave side of a conic section
Synonyms, antonyms and the broader and narrower relations for focus come from Princeton University’s WordNet. Full sources and licences.