1. Loud enough to shake the very earth 
2. Sufficiently significant to affect the whole world
   "earthshaking proposals"
   - world-shaking, world-shattering, earth-shattering

See also: important, loud, significant

• favor
• favorable
• favorable position
• favorable reception
• favorableness
• favorably
• favored
• favorite
• favorite son
• favoritism
• favour
• favourable
• favourable position
• favourable reception
• favourableness
• favourably
• favoured
• favourite
• favourite son
• favouritism
• favus
• Fawkes
• fawn
• fawn lily
• fawn-colored