noun (n)

• an exaggerated opinion of your own importance(noun.attribute)

  Synonym:
  self-importance, swelled head
  

  source: wordnet30
• an inflated feeling of pride in your superiority to others(noun.feeling)

  Synonym:
  ego, self-importance
  

  source: wordnet30
• The practice of too frequently using the word I; hence, a speaking or writing overmuch of one's self; self-exaltation; self-praise; the act or practice of magnifying one's self or parading one's own doings. The word is also used in the sense of egoism.(noun)

  source: webster1913