The Meaning of Liff is a humorous dictionary written by Douglas Adams and John Lloyd, published in 1983.

It is "[a] dictionary of things that there aren't any words for yet". All the words listed are place names, and describe common feelings and objects for which there is no current word. A typical example is:

Shoeburyness (abs.n.)
The vague uncomfortable feeling you get when sitting on a seat which is still warm from somebody else's bottom

According to Adams' account in The Salmon of Doubt, the Meaning of Liff grew out of an old school game, and started when he and Lloyd were on holiday together. The book is named after the place Liff.