serios Adjective, serios

1. serious, earnest
2. severe, stern

Appox. usage (any sense): 490 per million words

grav Adjective, grav

1. grave, serious
2. critical, important, weighty
3. severe, stern
4. earnest
5. baritone, low in pitch, tone

Appox. usage (any sense): 65.9 per million words