subnormal

Short definition from Wiktionary

Adjective

1. 1
   Less than normal.
2. 2
   denormal
3. 3
   idiot, stupid.

Noun

1. 1
   A person whose abilities are less than normal.
2. 2
   That part of the axis of a curved line which is intercepted between the ordinate and the normal.
3. 3
   Synonym of denormal.