The opposite of glitter is dullness.
dullness is how bright a color is, eg dull is very un-bright
Some words that rhyme with "dullness" are fullness, sullenness, and mulishness.
The dullness of the day was very depressing compared to the sunshine they had last week.
Definition of mental dullness; describing your personality and mind set to be bland with no effort to create enlightenment. Eg: a person with a basic brain with not much character has mental dullness
Dullness
Dullness
Constantly uninteresting
The closest you can get to it is just 'dullness'
the antonym is dullness and spirtlessness.
Lethargic. No energy, sluggishness, slowness or dullness. (No get up and go)
shadow, dark, depression, dullness