See also UNDESIRABLE.
hellacious
mod. terrible.The food was just hellacious. Yuck!The heat was hellacious, and the mosquitoes wouldn't leave us alone.
like death warmed over
mod. horrible; deathlike.Oh, my God! You look like death warmed over!A tall, blackgarbed gentleman lay there, looking like death warmed over.
unearthly
mod. weird; terrible.What was that unearthly noise?There was an unearthly smell coming out of the kitchen.That's not unearthly!
ungodly
mod. horrendous; inconceivable.What is that ungodly noise?What do you want at this ungodly hour?