That awkward mustache that some freshman and sophomores have that they really need to shave but won't because they:
1. don't yet notice it exists
2. think it's attracting the ladies
3. are grappling with accepting their blooming manhood.
In some unfortunate cases, a puberpiller will exist on the face of someone even older, in which case an intervention is due.
At first I thought he was cute, but then i noticed his puberpiller. It looked like an eyebrow fell down.