Example : An enormous boulder.
Enormous expenses.
Tremendous sweeping plains.
A tremendous fact in human experience; that a whole civilization should be dependent on technology.
A plane took off with a tremendous noise.

Synonyms : enormous

Example : A fantastic trip to the Orient.
The film was fantastic!.
A howling success.
A marvelous collection of rare books.
Had a rattling conversation about politics.
A tremendous achievement.

Synonyms : fantastic, grand, howling, marvellous, marvelous, rattling, terrific, wonderful, wondrous

Example : In a frightful hurry.
Spent a frightful amount of money.

Synonyms : awful, frightful, terrible