inferiority complex

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A persistent sense of inadequacy or a tendency to self-diminishment, sometimes resulting in excessive aggressiveness through overcompensation.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun a sense of inferiority; the feeling that one is inferior to others in certain aspects.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a sense of personal inferiority arising from conflict between the desire to be noticed and the fear of being humiliated