1. Horrible.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• gruesomley,
• aresome,
• gruesom,
• groosome,
• cruesome,
• gruseome,
• gruesomly,
• grousome,
• grusome,
• grumsome,
• resome,
• gruelsome,
• gruisome,
• grusom,
• greusome,
• crusome,
• grusesome,
• gresome,
• grewsome,
• guesome

• gruesomely,
• greasiness,
• grison,
• greeson,
• greisen,
• grissom,
• Grayson,
• gresham,
• grisson,
• resume,
• gregson.

The adverb form of "gruesome" is "gruesomely".

The adjective form of the word "gruesome" is "gruesome".

The plural form of the word "gruesome" is "gruesomes." However, "gruesome" is not commonly used as a plural, and it is more common to refer to multiple gruesome things or events using the singular form.

The singular form of the word "gruesome" is "grue"