Synonyms of the word

unplayful

• adj. Not playful.

serious

• adj. Without humor or expression of happiness; grave in manner or disposition; earnest; solemn.
• adj. Important; weighty; not insignificant.
• adj. Really intending what is said; in earnest; not jocular or deceiving.

sober

• adj. not drunk; not intoxicated.
• adj. not given to excessive drinking of alcohol.
• adj. moderate; realistic; serious; not playful; not passionate; cool; self-controlled.
• adj. dull; not bright or colorful.
• adj. subdued; solemn; grave.
• v. (often with up) To make or become sober.
• v. (often with up) To overcome or lose a state of intoxication.