Inferiority complex is defined as

1. In psychiatry: an intense feeling of inferiority, producing a personality characterized either by extreme reticence or, as a result of overcompensation, by extreme aggressiveness.
2. Lack of self-esteem; feeling of inadequacy; lack of self-confidence.
3. A persistent sense of inadequacy or a tendency to self-diminishment, sometimes resulting in excessive aggressiveness through overcompensation.
4. Sense of personal inferiority arising from conflict between the desire to be noticed and the fear of being humiliated.