Similar words
sério
grave is more about severity, like a grave illness; sério is more about demeanor, like a serious person not joking.
Similar in other languages
German
ernst
ernst is the German word for the same thing — both mean "serious."
Spanish
grave
grave is the Spanish word for the same thing — both mean "serious."
Spanish
serio
serio is the Spanish word for the same thing — both mean "serious."
Practice
1 What does grave mean?
serious
2 Fill the gap: É um problema ___.
Full sentence: É um problema grave. (It's a serious problem.)
3 Which fingerprint chart matches grave?
grave: neutral register, common frequency, general domain, neutral connotation.