I'm having fun going through the dictionary from A-Z.  Yes, page by page....
At 365 Word Quest I select a word a day and provide an etymology and context.  It's particularly interesting to see the sometimes convoluted origins of words.  Also on the sidebar I have widgets for the Oxford English Dictionary, Merriam-Webster Online, and Wordnik.  They each provide a word of the day.  If you appreciate language, you may  enjoy this cornucopia for the wordsmith.  
Here is a selection from the last few weeks.
cacophony- jarring sound, discordant, harsh
- also cacophonous, cacophonic
- from Greek kakos- bad
camaraderie- a spirit of familiarity and trust existing between friends
- C19 from French, from comrade
cantankerous- quarrelsome; irascible
- C18, from Anglo French, perhaps from C14 conteckour- contentious person from conteck strife
capricious-  characterized by or liable to sudden unpredictable changes in attitude or behaviour; impulsive; fickle
- caprice, capriciousness- noun
-from French, Italian capriccio- capo- head +riccio- hedgehog, suggesting a convulsive shudder of a hedgehog's spines
carpe diem- seize the day
-Latin from Horace
carte blanche- complete discretion or authority
-C18 from French- blank paper
catharsis- the purging or  purification of the emotions through the evocation of pity and fear, as  in tragedy; the bringing of repressed ideas or experiences into  consciousness, thus relieving tensions
-from Greek katharsis- to purge, purify
caveat emptor- let the buyer beware
-Latin
charisma- a special personal  quality or power of an individual making him capable of influencing or  inspiring large numbers of people; a quality inherent in a thing which  inspires great enthusiasm and devotion
-C17 from Latin, Greek kharisma, from kharis- grace, favour
charlatan- someone who professes knowledge or expertise, especially in medicine, that he does not have; quack
-C17 from French, from Italian ciarlare- to chatter
chauvinism- aggressive or  fanatical patriotism; jingoism; enthusiastic devotion to a cause; smug  irrational belief in the superiority of one's own race, party, sex- male  chauvinism
C19 from French chauvinisme- after Nicolas Chauvin- legendary French soldier under Napoleon, noted for his vociferous and unthinking patriotism
churl- a surly, rude,  ill-bred person
- Old English ceorl; Old Norse karl, Middle Low German kerle, Greek geron old man
- also adjective churlish
convivial- sociable; jovial or festive
-C17 from Latin convivium, a living together, banquet from vivere to live
Are there any words above which strike your fancy?