So today in one of my classes, a student says, "先生、あなたはしんどい"
I had never heard the word before (well, ok, maybe I have but I can't recall), so I immediately looked it up in my handy electronic dictionary. I highly recommend buying your own 電子辞書 (denshi jisho).
However, the word しんどい will very likely not appear in any modern electronic dictionary.
しんどい does appear in Jim Breen's online dictionary though.
Asking a reliable Japanese source, I learned that しんどい most closely means きつい (kitsui).
Now, though the dictionary definition linked above sounds as though the adjective can be used to describe a situation, location, or perhaps a feeling, the word きつい is primarily used to mean "tiresome" or "troublesome" as in:
授業がきついだねぇ～ (jyugyou ga kitsui da ne~)
"Class is tough...*unspoken sigh*"
However, I'm told that しんどい is "おばあちゃんの言葉" (obaachan no kotoba = grandmother language i.e. "A word my grandma would use"), so be careful if you're going to use the word - make sure you use it around people who would understand it's heritage as well as appreciate it in the sense that you're making fun of the word even while using it seriously.
I suppose by comparison, you could think of しんどい as being as culturally appropriate in 2005 as "swell" would be (for those less inclined to pick up on sarcasm, I'm laying it on rather heavily at the moment).
The new word of the day then should be "しんどい." Make sure to use it in your next class or when you see a Japanese friend next. I lament I cannot provide sound bites for pronunciation purposes, but if you manage to get the exasperated sigh going, you'll nail the spirit of the word perfectly and hopefully get a laugh.
Laughter is what life is all about anyway - if you don't mind a rare philosophical plug ^_^