The idiomatic expression "than a skirt" means that something is more desirable or preferable than wearing a skirt. It can be used in various contexts to express a preference for one thing over another, often when comparing two options. For example, if someone says they would rather go on a hike than stay home and watch TV, the phrase "than a skirt" could be added at the end of their statement to emphasize that hiking is more appealing to them than wearing a skirt.