I was intrigued to find that 50 years ago, one could get a "letter to Nature" published just on the grounds of having invented a new word. Though I have to admit that the word suggested by Karlson and Lüscher in January 1959 was indeed very useful, and today we really wouldn't know what to do without it. The word was "pheromone." The key element of their new definition, setting it apart from the previous attempt, ectohormone, was that it referred to substances secreted by an individual to be sensed by another individual of the same species. 50 years after this definition, we know a lot about animal pheromones, but the human variant and its perception has remained elusive.
The 1959 paper, just a page long, is online here.
There is also an essay (2 pages!) commemorationg the anniversary in this week's issue.
PS: To German biochemists, Peter Karlson is known as the author of a highly successful biochemistry textbook, possibly the first one to be written in German.