My current "dipping in" reading is An Encyclopedic Dictionary of language and Languages from which comes the following:
Amorite - A Semitic language spoken in the area of modern Northern Syria from c.2000 to c.1500 BC. Little is known about it because the evidence for its existence comes only from lists of proper names.
Boustrophedon - Writing in which the lines runs in alternate directions; the name derives from Greek and means "ox-turning"
Cocktail party effect - The process of selective listening
Ding-dong theory - One of the speculative theories about the origin of language; it argues that speech arose because people reacted to the stimuli of the world around them and spontaneously produced sounds which in some way reflected the environment.
Epicene - A noun which can refer to either sex without changing its form, e.g. teacher, doctor
Franglais - A language variety which is a non-standard mixture of French and English, and recognised by both the French and the English.
And so on - the best toilet reading since I read a book consisting of diary entries from famous diarists which covered exactly a year.