When people or things jade, they become dull, weary, and exhausted. And to jade people or things is to make them work too hard for too long, which makes them dull, weary, and exhausted.
So, if you're jaded, you're feeling dull, weary, exhausted, and unable to really care anymore, usually because you've been doing or experiencing the same things for way too long.
Part of speech:
Adjective: "a jaded perspective," "she was jaded."
Other forms: jadedly, jadedness
How to use it:
Talk about jaded people and their jaded views, thoughts, perspectives, personalities, feelings, hearts, faces, expressions, gestures, comments, etc.
Even though we rarely use the verb "jade" in the active voice (as in "it jaded her" or "the world has jaded him"), we do often use the passive voice and talk about people being (or getting) jaded by something: "the students are jaded by months of dull preparation for exams," "he was getting jaded by all these rejection letters."
These days, when we use this word, we're usually saying that people are jaded by bad things and experiences, but people can also become jaded by relatively good things, like an overabundance of luxuries.
Though we often say people are jaded by something, we can also say they're jaded about some sphere or topic: "he's jaded about politics these days," "she's still jaded about romance in general."
examples: In How the Grinch Stole Christmas, the Grinch's jaded heart is revived when he hears joyful singing even after the food and the gifts are stripped away.
"Perhaps you, too, are beginning to get jaded by the endless stream of best-dressed lists, the fawning adjectives dripping in brand names."