Neutral:
* Humorless: This is a straightforward and neutral description.
* Serious: This implies that the person is always serious and doesn't enjoy or appreciate humor.
* Unsympathetic: This describes someone who lacks empathy and understanding, often making them insensitive to humor.
* Lacking a sense of humor: This is a direct and simple statement.
Negative:
* Dour: This implies a gloomy and unsmiling demeanor.
* Grim: This suggests that the person is always serious and never lighthearted.
* Solemn: This emphasizes a serious and formal attitude.
* Stony-faced: This emphasizes a lack of expression or any sign of humor.
* Stiff: This implies that the person is rigid and unyielding, unable to relax and enjoy humor.
* Uptight: This suggests that the person is overly concerned with rules and formality, making them unable to appreciate humor.
Informal:
* Buzzkill: This describes someone who ruins the fun or enjoyment of a situation.
* Party pooper: Similar to "buzzkill," this term suggests someone who spoils the enjoyment of a social gathering.
* Grump: This implies that the person is always in a bad mood and finds it difficult to see the funny side of things.
* Stick in the mud: This implies that the person is old-fashioned and resistant to change or new ideas, often making them humorless.
Remember to choose a word that accurately reflects your intended meaning and the specific context of your statement.