Merriam-Webster Collegiate Dictionary - aggressive

 adjective  Date: 1824  1.  a. tending toward or exhibiting aggression ~ behavior  b. marked by combative readiness an ~ fighter  2.  a. marked by obtrusive energy  b. marked by driving forceful energy or initiative ; enterprising an ~ salesman  3. strong or emphatic in effect or intent ~ colors ~ flavors  4. growing, developing, or spreading rapidly ~ bone tumors  5. more severe, intensive, or comprehensive than usual especially in dosage or extent ~ chemotherapy  • ~ly adverb  • ~ness noun  • aggressivity noun Synonyms:  ~, militant, assertive, self-assertive mean obtrusively energetic especially in pursuing particular goals. ~ implies a disposition to dominate often in disregard of others' rights or in determined and energetic pursuit of one's ends was taught to be ~ in his business dealings. militant also implies a fighting disposition but suggests not self-seeking but devotion to a cause, movement, or principle militant protesters held a rally against racism. assertive suggests bold self-confidence in expression of opinion the more assertive speakers dominated the forum. self-assertive connotes forwardness or brash self-confidence a self-assertive young executive climbing the corporate ladder.