Almost afraid to ask. But what does that mean?
Mad Libs were a popular learning game in which inexpensive booklets contained a fifty or so pages of paragraphs with key words missing and the "players" would fill in the words with "pronouns," "verbs," etc. If you were really bored, something approximating hilarity would ensue. As you got older the temptation to fill in the blanks with "dirty words" became overpowering.