solemn

UK: /ˈsɒləm/ US: /ˈsɑləm/ ,(sol′əm)

WordReference Random House Learner's Dictionary of American English © 2025

sol•emn /ˈsɑləm/   adj. 

1. grave; not funny:
   solemn remarks.
2. serious;
   earnest;
   sincere:
   solemn assurance that he would keep his word.
3. of a ceremonious character:
   a solemn occasion.
4. marked or observed with religious rites:
   a solemn holy day.

so•lem•ni•ty /səˈlɛmnɪti/  n. [uncountable]
sol•emn•ly, adv. 

WordReference Random House Unabridged Dictionary of American English © 2025

sol•emn  (sol′əm), adj. 

1. grave, sober, or mirthless, as a person, the face, speech, tone, or mood:
   solemn remarks.
2. gravely or somberly impressive;
   causing serious thoughts or a grave mood:
   solemn music.
3. serious or earnest:
   solemn assurances.
4. characterized by dignified or serious formality, as proceedings;
   of a formal or ceremonious character:
   a solemn occasion.
5. made in due legal or other express form, as a declaration or agreement:
   a solemn oath.
6. marked or observed with religious rites;
   having a religious character:
   a solemn holy day.
7. uttered, prescribed, or made according to religious forms:
   a solemn ban on sacrifice.

• Late Latin sōlennis, sōlempnis, Latin sōlemnis, variant of sollemnis consecrated, holy, derivative of sollus whole
• Old French)
• Middle English solem(p)ne (1275–1325

sol′emn•ly, adv. 
sol′emn•ness, n. 
Synonyms

• 1. unsmiling, serious. See grave ².
• 2. august, imposing, stately.
• 4. ritual, ceremonial.
• 6. devotional, sacred.

Antonyms

• 1. humorous.
• 2. trivial.

Collins Concise English Dictionary © HarperCollins Publishers::

solemn / ˈsɒləm/ adjective

1. characterized or marked by seriousness or sincerity: a solemn vow
2. characterized by pomp, ceremony, or formality
3. serious, glum, or pompous
4. inspiring awe: a solemn occasion
5. performed with religious ceremony
6. gloomy or sombre: solemn colours

Etymology: 14th Century: from Old French solempne, from Latin sōllemnis appointed, perhaps from sollus whole

ˈsolemnly adverb

ˈsolemnness, ˈsolemness noun