portent, omen

(きち) 90% of the time this is only used in fortune-telling. Usually used like this 吉(きち)(good omen) or 不吉な兆し(ふきちなきざし)bad omen
(えんぎのわるい) This is used when there is a rule or superstition (i.e. black cat crosses your path, mirror breaks, ’tis bad luck to have a woman on board a ship! kind of thing).
(きっちょう) An omen – used when there is NO existing rule or superstition. You just see an event and decide arbitrarily to interpret it as good luck (“Aha! It’s raining! I’m going to put all my money on the horse called ‘Mr. Rain Balls’ to come in first place!”) ZZZ