Legal Definitions - collateral heir

A collateral heir is a person who is not a direct descendant or ancestor of the deceased, but is related through a collateral line, such as a brother, sister, uncle, aunt, nephew, niece, or cousin. This person is entitled to receive a portion of the deceased's property under the laws of intestacy.

For example, if a person dies without a will and has no surviving spouse or children, their property would be distributed to their collateral heirs, such as their siblings or nieces and nephews.