A more thorough explanation:

An omitted heir, also known as a pretermitted heir, is a child who has been left out of a deceased person's will or trust, but would have inherited from the estate as an heir if they had been included. This can happen when a child is born or adopted after the will or trust was created, and the document was not updated to reflect the change.

For example, if a person creates a will that leaves their entire estate to their two children, but then has a third child who is not included in the will, that child may be considered an omitted heir.

Most states have laws that allow omitted heirs to claim a share of the estate, as if the deceased person had died without a will. However, there are some exceptions to this rule. For instance, if the deceased person intentionally left the child out of the will, or if the child was provided for in another way, they may not be entitled to a share of the estate.

One example of an omitted heir statute is California's Probate Code § 21620–21622. This law allows children who were born or adopted after a will was created to claim a share of the estate, unless certain exceptions apply.

For instance, if the deceased person intentionally left the child out of the will, or if the child was provided for in another way, they may not be entitled to a share of the estate. Additionally, if the deceased person had one or more children and left most of their estate to the other parent of the omitted child, the child may not be entitled to a share.

Overall, an omitted heir is a child who would have inherited from a deceased person's estate if they had been included in the will or trust, but were left out due to an oversight or other reason.