Synonyms for grave

modified

1. Important

   momentous, weighty, consequential; see important 1.

2. Dangerous

   critical, serious, ominous; see dangerous 1.

3. Solemn

   serious, sober, earnest; see solemn 1. See syn. study at serious.

noun

1. A burial place

   vault, sepulcher, tomb, pit, crypt, mausoleum, catacomb, long home, burial chamber, burial pit, burial place, six feet of earth, last resting place, narrow house, place of interment, mound, barrow, cromlech, clay, cairn, tumulus, dolmen, cold mud*, pine*, wooden shroud*, pit for the dead*, charnel house*, last home*, permanent address*.

2. Death

   dissolution, decay, last sleep; see death 2.

make one turn (over) in one's grave*

have one foot in the grave*