arrogant — Someone who is arrogant behaves in a proud, unpleasant way towards other people because they believe that they are more important than others.
brash — If you describe someone or their behaviour as brash, you disapprove of them because you think that they are too confident and aggressive.
confident — If you are confident about something, you are certain that it will happen in the way you want it to.
presumptuous — full of, characterized by, or showing presumption or readiness to presume in conduct or thought, as by saying or doing something without right or permission.
self-confident — realistic confidence in one's own judgment, ability, power, etc.
bumptious — If you say that someone is bumptious, you are criticizing them because they are very pleased with themselves and their opinions.
certain — If you are certain about something, you firmly believe it is true and have no doubt about it. If you are not certain about something, you do not have definite knowledge about it.
cocksure — Someone who is cocksure is so confident and sure of their abilities that they annoy other people.
conceited — If you say that someone is conceited, you are showing your disapproval of the fact that they are far too proud of their abilities or achievements.
egotistical — Excessively conceited or absorbed in oneself; self-centered.
hotshot — highly successful and aggressive: a hotshot lawyer; a hotshot account exec.
hubristic — excessive pride or self-confidence; arrogance.
know-it-all — a person who acts as though he or she knows everything and who dismisses the opinions, comments, or suggestions of others.
lordly — suitable for a lord, as trappings or ceremonies; grand or magnificent.
nervy — brashly presumptuous or insolent; pushy: a nervy thing to say; a nervy trick to pull.
overweening — presumptuously conceited, overconfident, or proud: a brash, insolent, overweening fellow.
positive — admitting of no question: positive proof.
