I. -esiv, -ēv adjective
1.
a. : tending toward, characterized by, or practicing aggression
her aggressive behavior
an aggressive nation
b. : marked by combative readiness or bold determination : not conciliatory : militant
an aggressive fighter
2.
a. : marked by driving forceful energy, ambition, or initiative : enterprising
an aggressive salesman
aggressive leadership
b. : marked by obtrusive energy and self-assertiveness : demanding or attracting attention : self-confident
swaggering, blatant, and idiotically aggressive vulgarity — George du Maurier
3.
a. : promoting or accessory to aggression in predaceous animals (as insects) especially by concealment or disguise
an aggressive trait
b. botany : spreading with vigor
aggressive weeds
c. : chemically active
aggressive waters
d. : tending or able to utilize a variety of habitats : able to encroach on occupied areas : variable and adaptable — used of organisms and taxa
an extremely aggressive subspecies
Synonyms:
militant , assertive , self-assertive , pushing , pushful : aggressive may apply either to zealous loyalty to causes or to personal ambitions and aims; it suggests forceful and confident procedures and attitudes, sometimes truculent contentiousness or cavalier treatment of others
positive in his convictions, aggressive and imperious, he became a zealot in any cause he embraced — F.L.Hise
as intolerant and aggressive as any of the traditional satirists — C.D.Lewis
militant , complimentary except for suggestions of doctrinaire intractability, applies to fervent, resolute, devoted furthering of a cause
the militant suffragist nuisance — Rose Macaulay
militant in fighting to get for workers a larger share of the national income — Time
assertive suggests bold self-confidence and determination in expression of opinion
an assertive, opinionated, likable fellow, ready to fight, drink, dance, shoot, or brag — V.L.Parrington
to say, with some challenging assertive people, that trees are more beautiful than flowers — E.V.Lucas
self-assertive , usually uncomplimentary, generally connotes obtrusive, crass forwardness or brash self-confidence
the social and political revolt beginning in the new middle class against the Tory aristocracy found more vigorous expression in the self-assertive and ubiquitous energy of Henry Brougham — G.M.Trevelyan
self-assertive and ill-bred bourgeois — Edmund Wilson
pushing and pushful may praise by indicating ambition, energy, and enterprise
an energetic, pushing youth, already intent on getting on in the world — Sherwood Anderson
the pushful energetic man of business — Aldous Huxley
or blame by indicating snobbish or crude intrusiveness
a pushing sort, forever exposing themselves to the slights arising from their own undesirability — Mary Austin
ignorant, pushful, impatient of restraint and precedent — H.L.Mencken
II. adjective
: more severe, intensive, or comprehensive than usual especially in dosage or extent
aggressive chemotherapy