• 子孫しそん — descendants
• 内孫うちまご — grandchild from a son
• 孫娘まごむすめ — granddaughter

孫 combines the idea of “child” (子) with elements of lineage, pointing to one’s descendants. The most familiar usage is 孫まご, but in compounds the on-yomi ソン is common (子孫, 外孫).