Serious and solemn (5)
I believe the answer is:
grave
(Other definitions for grave that I've seen before include "of importance" , "Hazardous" , "In which to lay a corpse" , "Burial site" , "Solemn; tomb" .)
I believe the answer is:
grave
(Other definitions for grave that I've seen before include "of importance" , "Hazardous" , "In which to lay a corpse" , "Burial site" , "Solemn; tomb" .)