When a really fat girl tries to smush her fat self into clothing that she has no business wearing. Can be seen wearing halter tops, hot pants, bikinis, belly shirts, low-rise jeans, generally wears clothing that should only be worn by thin girls. Thinks she looks great in it!
Oh my god, look at the one in the tube top and the hot pants over there...she must have REVERSE ANOREXIA! She must weigh 150 pounds, doesn't she realize how fat she is?
Low self-esteem in weight-lifters (called 'exerslaves'), who lift and -- psychologically, see no gain.
Has many synonyms:
-Muscle dysmorphia (reverse anorexia is considered one of the BDDs, or body dysmorphic disorders a.k.a. dysmorphophobia/ imagined ugliness syndrome, or dysmorphic concern).