The word crazy has two main definitions. One is "mentally deranged" and the other takes on a more positive connotations, as either an adverb or adjective meaning "interesting" or even "enthusiastic". The word is slowly shifting towards the latter over time. However, in the past, the word was created by the addition of a -y to the word craze, which at the time meant "diseased" or "sickly", as in she was in a craze, This went through several alterations as we go further back in history, including crase, craize, and craise, but most etymologists agree that this traces to the Middle English word craisen, or "to break", apparently because a sick person is "broken". This allegedly derives from Old Norse krase, or "to shatter", from an unknown origin. An interesting antonym which is almost a homonym: most of the Slavic languages have something similar to the Polish krasa, which meant "beauty".
Adam Aleksic, a leading contender for valedictorian of his high school, is a 208-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and just won an essay contest on linguistics!
The Etymology Nerd