Aprioritron
An aprioritron was a component of TARDISes. Marnal mentioned the aprioritron as one of the important parts of the Doctor's TARDIS that wasn't working. (PROSE: The Gallifrey Chronicles)
It should be relocated at Aprioritron because its the same word
Talk about it here or check the revision history for additional comments.
On entering the War Master's TARDIS control room, the Eighth Doctor noted that the a prioritron, the randomiser and the safety locks were still operational. (AUDIO: The Castle of Kurnos 5)
Behind the scenes
In philosophy, something a priori can be known without sense experience, coming before experience, as contrasted with a posteriori knowledge, which is gained through interaction with the world. These terms are central to Immanuel Kant's pursuit of synthetic a priori knowledge, a priori knowledge which is not based on the meaning of the words in the statement. (e.g. "All bachelors are unmarried" would not qualify.)
Etymologically, the suffix -tron refers to an instrument or device, things one would typically use in the formation of a posteriori knowledge, rather than a priori.
External links
A Priori Justification and Knowledge at the Stanford Encyclopaedia of Philosophy
The Analytic/Synthetic Distinction at the Stanford Encyclopaedia of Philosophy
