Meriam Webster calls it a relatively stable level, period, or condition.

World English Dictionary says that it’s a leveling off.

The Mayo Clinic refers to a (weight loss) plateau as the point where your body stops losing weight, even though you’re still eating a low-calorie diet and working out:

“A plateau occurs because your metabolism — the process of burning calories for energy — slows as you lose lean tissue (muscle). When you lose weight, you lose both fat and lean tissue. (The notion that overweight people have a slower metabolism is a myth. In general, the higher a person’s weight, the higher the body’s metabolic rate.) Your weight-loss efforts result in a new equilibrium with your now slower metabolism. This means that in order to lose more weight, you need to increase activity or decrease the calories you eat. Using the same approach that worked initially will maintain your weight loss, but it won’t lead to more weight loss.”

Personally, I’m currently defining “plateau” as 160.0.

That’s right, I woke up at 160.0 lbs again today.  The cosmic laugh track is looping.  I am not amused.

As for the Mayo Clinic’s opinion that I need to up my exercise, I completely agree.  This whole thing with missing Bikram classes is just out of hand right now.  It’s Day 13 of my 30 Day Bikram Challenge, and I’ve only got 9 classes to show for it.  In a couple of hours, I’m ducking out of work and heading to a 4:30 class, then sticking around to make it a double work out.  Hopefully I can do the same thing a couple of more times this week, and maybe even get ahead of schedule.  It would be awesome to be 159 by Friday.  Who knows, maybe I could even be 158!