Definitions of grave:

• noun:   a place for the burial of a corpse (especially beneath the ground and marked by a tombstone)

  Example: "He put flowers on his mother's grave"

• noun:   death of a person

  Example: "He went to his grave without forgiving me"

• noun:   a mark (`) placed above a vowel to indicate pronunciation
• verb:   carve, cut, or etch into a material or surface

  Example: "Engrave a pen"

• verb:   shape (a material like stone or wood) by whittling away at it
• adjective:   of great gravity or crucial import; requiring serious thought

  Example: "Grave responsibilities"

• adjective:   dignified and somber in manner or character and committed to keeping promises

  Example: "A grave God-fearing man"

• adjective:   causing fear or anxiety by threatening great harm

  Example: "A grave situation"

• name:  A surname (very rare: popularity rank in the U.S.: #21558)