(めいよ) An honor or prestige that comes in the form of a seal of approval or bonus points from an authority figure. Usually used like this:名誉なこと. 名誉を受けた。
(こうえい) Usually used by lower person to higher person. “It’s an honor to meet you, sir!” “I’m honored to have a chance to work with you, ma’am.”
(いさぎよさ) Unlike 名誉 and 光栄, 潔さ happens even if no one is looking. 潔さ means someone who puts principle above everything else – someone who will turn down a job offer from a mob-connected business, even if they are really broke and don’t have enough to eat. This is also the word used about guys who commit suicide for honor.
(せいちょく) Can mean honorable – well, no. A 正直な人 is more like an ‘honest person’ or  ‘a person of integrity.’ But 90% of the time you see 正直, it’s not about a person’s personality at all. It usually means ‘Honestly, I think blah blah blah.’