Cheerlessness is a synonym of mirthlessness.
As nouns the difference between mirthlessness and cheerlessness
is that mirthlessness is the state or condition of being mirthless while cheerlessness is the state or characteristic of being cheerless.
mirthlessness
English
Noun
(-)
The state or condition of being mirthless.
Synonyms
* cheerlessness, infestivity, joylessness
cheerlessness
English
Noun
(-)
the state or characteristic of being cheerless
Synonyms
* infestivity, joylessness, mirthlessness