Adjective

(en-adj)

Without humor or expression of happiness; grave in manner or disposition; earnest; thoughtful; solemn.

It was a surprise to see the captain, who had always seemed so serious , laugh so heartily.

Important; weighty; not trifling; leaving no room for play; needing great attention; critical.

This is a serious problem. We'll need our best experts.

Really intending what is said; being in earnest; not jesting or deceiving; meaningful.

After all these years, we're finally getting serious attention.

Adjective

(er)

Very bad or intense.

* {{quote-magazine, date=2012-01

, author=Donald Worster , title=A Drier and Hotter Future , volume=100, issue=1, page=70 , magazine= citation , passage=Phoenix and Lubbock are both caught in severe drought, and it is going to get much worse. We may see many such [dust] storms in the decades ahead, along with species extinctions, radical disturbance of ecosystems, and intensified social conflict over land and water. Welcome to the Anthropocene, the epoch when humans have become a major geological and climatic force.}}

Strict or harsh.

Sober, plain in appearance, austere.