Lawful Issue Law and Legal Definition

The phrase 'lawful issue' has the same meaning as the words 'issue' and 'lineal descendants'. The term 'issue' when used in the context of wills means all of a person's children or other lineal descendants such as grandchildren and great-grandchildren. The term does not include all heirs, but only the direct bloodline.

In the past, statutes governing wills used the term legal issue to refer children born to married parents, and to exclude those born out of wedlock. At common law it is unquestionable that the only issue who were considered "lawful" or legitimate were those who were the children of a legally recognized subsisting marriage. [In re Estate of Sheffer, 139 Misc. 519, 521 (N.Y. Sur. Ct. 1931)].