center has 40 distinct synonyms spread across 15 of its 23 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 2 recorded opposites are right, left.
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.
an area that is approximately central within some larger region
“it is in the center of town”
the piece of ground in the outfield directly ahead of the catcher
“he hit the ball to deep center”
a building dedicated to a particular activity
“they were raising money to build a new center for research”
a point equidistant from the ends of a line or the extremities of a figure
the choicest or most essential or most vital part of some idea or experience
“the gist of the prosecutor's argument”
the object upon which interest and attention focuses
“his stories made him the center of the party”
a cluster of nerve cells governing a specific bodily process
“in most people the speech center is in the left hemisphere”
the middle of a military or naval formation
“they had to reinforce the center”
(basketball) the person who plays center on a basketball team
a place where some particular activity is concentrated
“they received messages from several centers”
politically moderate persons; centrists
(ice hockey) the person who plays center on a hockey team
mercantile establishment consisting of a carefully landscaped complex of shops representing leading merchandisers; usually includes restaurants and a convenient parking area; a modern version of the traditional marketplace
“a good plaza should have a movie house”
the position on a hockey team of the player who participates in the face off at the beginning of the game
(American football) the position of the player on the line of scrimmage who puts the ball in play
“it is a center's responsibility to get the football to the quarterback”
a position on a basketball team of the player who participates in the jump that starts the game
Synonyms, antonyms and the broader and narrower relations for center come from Princeton University’s WordNet. Full sources and licences.