air

aircraft

alarm

alert

attack

attention

base

basketball

boat

buoy

buzzer

carrier

caution

creepy

critical

danger

dangerous

detector

device

drone

eerie

emergency

factory

fire

force

frightening

game

haunting

horn

infection

military

navy

ominous

prison

safety

scary

sci-fi

scifi

ship

signal

sinister

siren

spooky

submarine

system

threatening

tone

war

warning

yard

haunt

sci fi

threaten