concentrate

(transitive, intransitive) To bring to, or direct toward, a common center; to unite more closely; to gather into one body, mass, or force.

To increase the strength and diminish the bulk of, as of a liquid or an ore; to intensify, by getting rid of useless material; to condense.

To approach or meet in a common center; to consolidate.

(intransitive) To focus one's thought or attention (on).