1: the ability in which to resemble a
retarded person in behavior by being limited in
intellectual or emotional development---often taken to be offensive
2: the development or academic progress of retarding others
3: the act or instance the extent to which something
may be affected with retardedness
You're so naturally retardable, playing the
part of a mentally challenged person comes easily to you.
I'm sorry I keep screwing things up, I'm feeling
quite retardable
today.
That was very retardable of you to remember to flush the toilet, but forget to wipe.