The Word of the Day for Tuesday, Sept. 23, 2025, is "ephemeral." The word “ephemeral” captures this essence — that things are only meant to last temporarily. Here’s what you need to know about the word “ephemeral.”What is the definition of ‘ephemeral?’The word ephemeral means “lasting for a very short time.”It’s often used to describe things that are fleeting, temporary or short-lived. The word “ephemeral” is pronounced /ih-FEM-er-uhl/. The meaning of the word “ephemeral” expanded over time in the 1700s to describe short-lived insects and flowers.