big
big-league
big-name
big-time
bigwig
bigwigged
booming
consequential
considerable
deafening
double-barreled
ear-piercing
ear-rending
ear-splitting
earthshattering
forte
fortissimo
full
grand
great
heavyweight
high-powered
important
loud
loud-sounding
loudish
major
material
momentous
name
pealing
piercing
plangent
resounding
ringing
self-important
significant
sonorous
stentoraphonic
stentorian
stentorious
substantial
superior
thunderous
tonitruant
tonitruous
window-rattling
world-shaking