1. Seriously: This is the most common meaning. "Gravely" means something is serious or important. For example:
* "The doctor looked at her gravely." (The doctor looked serious, perhaps concerned)
* "The situation is grave." (The situation is serious and worrying)
2. Solemnly: "Gravely" can also mean in a solemn or formal manner. For example:
* "He spoke gravely about the loss of his friend." (He spoke in a serious and respectful way)
* "She bowed gravely to the audience." (She bowed in a formal and respectful way)
3. In a way that indicates danger or death: This is a less common meaning. For example:
* "He was gravely injured in the accident." (He was seriously hurt, possibly to the point of death)
To be sure of the meaning, you need to consider the context in which the word "gravely" is used.