1. The pieces of cloth that infants were once wrapped in, so as to limit their movement. The phrase is perhaps most commonly associated with the story of Jesus' birth: "And she brought forth her firstborn Son, and wrapped Him in swaddling clothes." Mama wrapped your babe in swaddling clothes and took him to the wet nurse so you could rest.

2. Strict limitations imposed upon the young and immature. Teenagers need swaddling clothes too, in the form of curfews and chores.

3. A period at the start of something. It can refer to a person's youth or to the early stages of an idea or project. In my mind, my son is still in his swaddling clothes—I can't believe he's about to start middle school. This idea is still in its swaddling clothes, so it might sound a little rough right now.