extremely hot; "the fervent heat...merely communicated a genial warmth to their half-torpid systems"- Nathaniel Hawthorne; "set out...when the fervid heat subsides"- Frances Trollope
requiring effort or concentration; complex and not easy to answer or solve; "raised serious objections to the proposal"; "the plan has a serious flaw"
of great consequence; "marriage is a serious matter"
concerned with work or important matters rather than play or trivialities; "a serious student of history"; "a serious attempt to learn to ski"; "gave me a serious look"; "a serious young man"; "are you serious or joking?"; "Don't be so serious!"
to the greatest degree or extent; completely or entirely; (`full' in this sense is used as a combining form); "fully grown"; "he didn't fully understand"; "knew full well"; "full-grown"; "full-fledged"