A very flat booty. Usally people with one either hate themselves or think that they don't have one.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

Having no ass or junk in the trunk. Suffering from the vitamin deficiency Noassitol. See Glutius Flatosis.

Blunt honesty, absolute truth bare of cushioning social niceties

Derives from the impossibility of reassuring a person with insufficiently pleasing buttocks

A twenty-first century version of the secretarial spread, caused by passing long hours planted in front of a computer. Also related to phone ear.

Of or pertaining to geniune truth. That which is true on the basest level.

A re-working of the expression flat out. Ultimate or distinguished from others by a high concentration of the quality expressed