egotism

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

• noun An inflated sense of one's own importance; conceit. synonym: conceit.

from The Century Dictionary.

• noun The practice of putting forward or dwelling upon one's self; the habit of talking or writing too much about one's self.
• noun Hence An excessive esteem or consideration for one's self, leading one to judge of everything by its relation to one's own interests or importance.
• noun Synonyms Pride, Egotism, Vanity, Conceit, Self-conceit, Self-consciousness. Pride and egotism imply a certain indifference to the opinions of others concerning one's self. Pride is a self-contained satisfaction with the excellence of what one is or has, despising what others are or think. Vanity is just the opposite; it is the love of being even fulsomely admired. Pride rests often upon higher or intrinsic things: as, pride of family, place, or power; intellectual or spiritual pride. Vanity rests often upon lower and external things, as beauty, figure, dress, ornaments; but the essential difference is in the question of dependence upon others. Over the same things one person might have pride and another vanity. One may be too proud to be vain. Conceit, or self-conceit, is an overestimate of one's own abilities or accomplishments: it is too much an elevation of the real self to rest upon wealth, dress, or other external things. Egotism is a strong and obtrusive confidence in one's self, shown primarily in conversation, not only by frequent references to self, but by monopolizing attention, ignoring the opinions of others, etc. It differs from conceit chiefly in its selfishness and unconsciousness of its appearance in the eyes of others. Conceit becomes egotism when it is selfish enough to disparage others for its own comparative elevation. Self-consciousness is often confounded with egotism, conceit, or vanity, but it may be only an embarrassing sense of one's own personality, an inability to refrain from thinking how one appears to others; it therefore often makes one shrink out of notice.
• noun Something which befalls you may seem a great misfortune;—you … begin to think that it is a chastisement, or a warning …. But give up this egotistic indulgence of your fancy; examine a little what misfortunes, greater a thousand fold, are happening, every second, to twenty times worthier persons; and your self-consciousness will change into pity and humility.

from the GNU version of the Collaborative International Dictionary of English.

• noun 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.

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

• noun A tendency to talk excessively about oneself.
• noun A belief that one is superior to or more important than others.
• noun Egoism.
• noun countable The result or product of being egoistic.

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

• noun an exaggerated opinion of your own importance
• noun an inflated feeling of pride in your superiority to others