Trivia is a relatively recent word - its first recorded usage, according to the OED, is 1902. It is more likely these days to be followed by a singular verb than a plural one, but etymologically, trivia is the plural of the Latin word trivium (just as bacteria is the plural of bacterium).
In the medieval era university education was based on seven liberal arts and the first three - grammar, rhetoric and logic - were called the trivium. These were studied first in order to give students a sound foundation to continue with the quadrivium, namely arithmetic, geometry, music and astronomy, and thus achieve a fully rounded education. The contrast between the three earlier subjects, considered less important, and the later four, gave us the adjective trivial (first attested with the meaning "unimportant" in the early 17th century).
Susan,
Speaking of trivia and things trivial, would you happen to know the genesis of the expression "going over (something) with a fine-tooth comb"?
Posted by: john | August 06, 2012 at 03:33 PM
Thanks, John. I'll hazard a guess. A fine-tooth comb is one whose teeth are set very close together. It's not great for untangling wet or knotted hair, but when I was a child most families had a fine-toothed comb to deal with the perennial problem of nits (they probably still do). If you combed a child's infested hair with an ordinary comb, the louse eggs wouldn't budge, but the fine-tooth comb would dislodge them, and they could be combed right out of the hair.
So, the idiom means to be very detailed and thorough. The OED doesn't have the 'go over' version, but it does have the idiom 'to rake hell with a fine tooth-comb'.
Posted by: Virtual Linguist | August 06, 2012 at 09:03 PM