Answer:

solemn

Answer	Crossword Clue
SOLEMN	Serious
SOLEMN	Unsmiling
SOLEMN	Eggshibiting gravity

SOLEMN	Invoking the force of religion
SOLEMN	Like funeral marches
SOLEMN	Like many a ceremony
SOLEMN	Like vows
SOLEMN	Heavy
SOLEMN	Long-faced
SOLEMN	Like most church services
SOLEMN	Grave

SOLEMN	Mirthless
SOLEMN	Not at all light
SOLEMN	Extremely earnest
SOLEMN	Like many oaths
SOLEMN	Very serious
SOLEMN	Gloomy
SOLEMN	Extremely serious
SOLEMN	Like High Mass

SOLEMN	Somber
SOLEMN	Heartfelt
SOLEMN	Seriously ceremonious
SOLEMN	Dour
SOLEMN	Grave and dignified
SOLEMN	Ceremonious
SOLEMN	Of a serious nature
SOLEMN	Dirgelike

SOLEMN	Marked by formality
SOLEMN	Like a moment of silence
SOLEMN	Far from frivolous
SOLEMN	Word from the Latin for "holy"
SOLEMN	Deeply earnest
SOLEMN	Gravely formal.
SOLEMN	Formal.
SOLEMN	Highly formal.

SOLEMN	Deeply earnest.
SOLEMN	Awe-inspiring.
SOLEMN	Grave.
SOLEMN	Sober
SOLEMN	Awe-inspiring