invader
Uninvited armed arrival
An invader is someone or something that enters by force or without permission—typically a military force crossing into another country's territory: The invaders swept through the countryside.
The term extends to anything unwelcome that intrudes: invasive species are ecological invaders, and viruses are invaders of the body.
In video games, Space Invaders established a genre.
Victor who takes control
- attackerOne who strikes first
- assailantOne who attacks another
- raiderOne who attacks suddenly
- occupierOne possessing a space
aggressor · warrior · combatant · marauder · plunderer · besieger · pillager · usurper
Unlawful entrant on property
- burglarOne who breaks in
- prowlerOne who lurks suspiciously
- infiltratorOne who enters covertly
- spyCovert information gatherer
housebreaker · stalker · interloper · thief · saboteur · scout · sneak · breach
One who occupies foreign land
- settlerOne who colonizes territory
- imperialistAdvocate for territorial expansion
- conquistadorSpanish colonial soldier-explorer
- occupierOne possessing a space
empire · territory · expansion · annexation · dominion · subjugation · exploitation · indigenous
Source of potential harm
adversary · hostile · aggression · defense · protection · fortification · vigilance · deterrence
Disease-causing microorganism
- virusMicroscopic infectious agent
- bacteriaNucleus-free single-celled organisms
- parasiteOne exploiting a host
- microbeMicroscopic living organism
infection · contagion · germ · pest · infestation · weed · disease · epidemic
Being from outer space
- UFOUnidentified aerial craft
- spaceshipVehicle for interplanetary travel
- abductionUnlawful seizure of person
- sci-fiFuturistic fiction, abbreviated
otherworldly · interstellar · cosmic · galactic · mothership · pod people · body snatchers · tentacles
conqueror
Victor who takes control
occupier · aggressor · warrior · combatant · marauder · plunderer · besieger · pillager · usurper · subjugator
trespasser
Unlawful entrant on property
- burglarOne who breaks in
- prowlerOne who lurks suspiciously
- infiltratorOne who enters covertly
spy · housebreaker · stalker · interloper · thief · saboteur · scout · sneak · breach · alarm
colonizer
One who occupies foreign land
- settlerOne who colonizes territory
- imperialistAdvocate for territorial expansion
- conquistadorSpanish colonial soldier-explorer
occupier · empire · territory · expansion · annexation · dominion · subjugation · exploitation · indigenous · native
menace
Source of potential harm
foe · adversary · hostile · aggression · defense · protection · fortification · vigilance · deterrence · warning
pathogen
Disease-causing microorganism
- virusMicroscopic infectious agent
- bacteriaNucleus-free single-celled organisms
- parasiteOne exploiting a host
microbe · infection · contagion · germ · pest · infestation · weed · disease · epidemic · immune response
extraterrestrial
Being from outer space
- UFOUnidentified aerial craft
- spaceshipVehicle for interplanetary travel
- abductionUnlawful seizure of person
sci-fi · otherworldly · interstellar · cosmic · galactic · mothership · pod people · body snatchers · tentacles · ray gun
- Plundererslooter, marauder, pillager, plunderer, raider
- Aggressorsaggressor, attacker, assailant, warmonger, belligerent
- attackersaggressor, assailant, attacker, assaulter, ambusher
- intrudersintruder, trespasser, burglar, prowler, infiltrator
- MartianMarvin the Martian, little green men, War of the Worlds, Mars Attacks, My Favorite Martian
- dangersdanger, peril, hazard, risk, menace
invaderdefender
One who guards another
protector · guardian · liberator · resistance fighter · freedom fighter
invadernative
Originating from a place
inhabitant · resident · local · citizen · host
invaderpeacemaker
Conflict resolution agent
pacifist · dove · nonbelligerent · diplomat · mediator
- home invadersPeople illegally entering residences
- Space InvadersClassic alien shooter arcade
- alien invaderHostile being from space
- pitch invaderUnauthorized person entering playing field
- lawn invader
invade, invading, invaded, invades, invaders, reinvaded, reinvade, uninvaded