(historical) A single page containing the alphabet, covered with a sheet of transparent horn, formerly used for teaching children to read.

(organic chemistry, obsolete) asparagine

A native or inhabitant of the ancient city of Troy. / A student (especially an athlete) of the University of Southern California. / (astrophysics) A Trojan asteroid.

(rare) The encoding of messages in such a way that they are as easy as possible to decipher.