T.E.D. has a fine answer, just wanted to say it my way. "Proverbial" means "having to do with a proverb", or as T.E.D. says "as heard in a proverb". There are many well-known proverbs in colloquial English. For example, there is one, "people in glass houses shouldn't throw stones", meaning that people in a precarious moral position shouldn't point out the failings of others. English proverbs are generally allegorical, similar to a biblical parable (and some parables, such as the parable of the mustard seed, and other biblical stories like David and Goliath, have remained popular in English even as the culture trends toward the secular). Some are poetic, such as "beer before liquor, never been sicker" (meaning if you start out an evening drinking beer, then progress to hard liquor, you'll have a bad hangover in the morning), and contrary to the connotation of the word "proverb" as imparting ancient wisdom, proverbs are invented all the time ("loose lips sink ships" was coined in World War II, in the months leading up to the D-Day invasion; it was such a big operation with so much of the military and industry involved that the U.S. Government basically asked the entire country to keep whatever they knew or suspected about it secret).
So, a person who talks about "the proverbial man in a glass house" is referring to the proverb in my first example. Where the proverb is known, its imagery can be evoked without recounting it fully.
"Proverbial" can also be used as a synonym for "idiomatic", having a similar meaning but relating instead to idioms. Idioms are popular, somewhat metaphoric sayings regarding common situations; for example:
- Up a creek without a paddle (in trouble with no way of helping yourself)
- Out on a limb (at serious risk for injury to body, reputation, or pride)
- Getting up on the wrong side of the bed (starting the day in a bad mood)
- Getting cold feet (becoming nervous about something one is about to do)
- The pot calling the kettle black (calling someone else out for a flaw you obviously possess yourself)
These sayings can also be referred to "proverbially", even though they're idioms; you may hear of being "up the proverbial creek", which is simply an alternate way of saying "up a creek without a paddle" as the original term has become slightly cliche.
This refers to having a "double period" of history, or two periods in a row.
When I went to high school in Australia in the '80s a period was typically 40 mins, with 8 per day. Double, and occasionally triple, periods were scheduled to allow for a longer uninterrupted block of teaching time.
The reason for using the phrase "double history" in the context you describe may be nothing to do with history per se. It's more likely used to suggest to the audience that the student in question considers a double period to be an excruciating length of time to have to sit next to your ex-girlfriend.
Best Answer
A potted history is brief, a quick summary. Potted meat is meat, usually not of the highest quality, processed and preserved in a tin. The expression is often used in a derogatory way, as it is in your example.
Let's see... yes, Merriam Webster gives as an example quote under "potted":
But, if you were to say, for example, "In the interest of time, I'll just give a potted history of this...", there would be no negative connotation.
This does not correspond to the American "canned", which carries the strong connotation of artificial and stale. "Canned history" would be understood and humorous, but it is not an idiom. In American, "the cliff-notes version" is often used, from a well-known series of booklets for students of brief, condensed summaries of famous texts. This too is often but not always used in some derogatory sense.