Lyam is a spelling variant of Liam, the Irish short form of William, which comes from the Germanic Willahelm and means "resolute protector". The y-spelling is common in France and Quebec and gives the most popular American boys' name a slightly different look on paper. Lyam was barely recorded in the United States in 2000; it has moved up from number 1662 in 2015 to number 1086 in 2025, its best rank so far.