When you've been doing something self destructive for some time (perhaps without realizing it) before something serious happens that forces you to come to terms with what you've been doing and that you need to stop.

Usually involves something medical but can involve anything serious.
He used to eat tons of junk food, stuff with all sorts of sugar, salty snack foods, you name it. It doesn't help that he rarely exercised. He didn't seem to get that even the manufacturers of those foods stress the importance of a balanced diet. His wake up call was a heart attack that almost killed him. Fortunately, he took it seriously and made a lot of changes to his lifestyle.

They used to seem like they had everything. They lived well beyond their means. Most people thought they were rich. It took almost losing their house for them to start opening their eyes and living within their means. It was a real wake up call.
by Optimist with experience April 14, 2009
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an event so dramatic or troubling that it effectively serves as an alert, reminder or call to action
The failure of the ongoing efforts to produce effective solutions should have been a wake up call to stop arguing.
by The Return of Light Joker September 7, 2009
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Oral sex between 6 and 8 a.m.
Everyone deserves a wake up call...
by skorpionlady August 13, 2005
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When you wake someone up by ripping a loud fart in their ear or face. A common prank played on those who like to sleep in at boy scout camp, church camps, fraternities, and boot camp. While likely done do a lesser extent, girls also have been known to participate in this activity at slumber parties. Please note the difference between this definition and "sound the alarm"
Frank is still sleeping and we need to leave in 10 minutes, so why don't you give him a wake up call to get him out of bed.
by Trumplodyte July 8, 2019
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a surprise and swift insertion of your hog leg into a friends mouth mid-yawn.

Man (to friend): oh, am i keeping you awake? you better not yawn again or you're getting a wake up call.

Friend (yawning): aaaaaaaahhhhhhh...AHH!!!
by johnnyg11141983 March 19, 2010
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In the morning, or anytime of the day, when the victim is taking a shower you go into the bathroom and take a large smelly shit and then flush the toilet. By flushing the toilet, the water temperature changes causing the victim to run out of the shower and smell the stench filled air. Best done in the morning, hence wake up call.
6:30 AM
Roy: Ahhh ahhhh cold cold, *cough* *cough* *gag* *gag* what the...damn it.....MIKEY!!!!!!!
Mikey: Hahahaha wake up call!!!!!!

Manager: Why are you late today Duncan?
Duncan: Sorry it's too obscene to mention
Manger: What?
Duncan: I stayed the night at my friend's house and he gave me a wake up call.
by window shopper June 20, 2011
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waking up with what appears to be a dead prostitute in your bed, typically used for pranks.
Jon got black-out drunk last night and woke up with a dead hooker in his bed, classic vegas wake-up call.
by eljpac March 2, 2011
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