Faire la grasse matinée

What a luxury to pull a fluffy pillow over your ears while the birds break the silence of the night at the first light of day!  Faire la grasse matinée is one of the true pleasures in life - and certainly the most practiced sport among teenagers.  It litterally translates to do the fat morning, and means to stay in bed, awake or not, longer than usual and on purpose.  In short: to sleep in.

Note that the expression is often shortened to faire la grasse mat'.

The question that naturally comes to mind is: What's fat to do with staying in bed late? Does it mean you'll splurge on butter croissants once you finally emerge from sleep?

Origin

Originally, the expression was dormir la grasse matinée - to sleep the fat morning - where grasse came from the Latin "crassus," meaning fat as well as thick or deep.  It seems that the original meaning was more "to stay a long time in the depth/thickness of sleep," rather than having anything to do with fat.

From the 17th century onwards, however, we find references to women from the high society who lounge late in the morning to "put on fat."  We are talking about a not so distant past when the fair sex proudly displayed their curves rather than hiding them.  The plumper you were, the more desirable.  In those pre Dunkin' Doughnuts days, putting on weight would have been hard work for many who couldn't afford to stuff themselves with fattening foods, let alone staying in bed all morning.   And if spending the morning in bed could help, then faire la grasse matinée would have made as much sense then as hitting the gym at 7am today.  Adding a couple of croissants couldn't hurt either - then, or now.

Examples

Chez moi, on fait toujours la grasse matinée le dimanche.
At my house, we always sleep in on Sunday.

La société, sauvée encore une fois, se félicitait, se reposait, faisait la grasse matinée, maintenant qu’un gouvernement fort la protégeait. La Curée par Émile Zola
Society, saved once again, congratulated itself, rested, had a lie-in, now that a strong government was protecting it. The Kill by author Émile Zola