1. the state of mind of Jeremy Lin fans when he steps on the court. and off the court. this highly contagious phenomenon has led to a series of wins by the Knicks, an increased basketball fandom among the Asians, and the creation of other words with 'lin'
2. basically anything that Jeremy Lin does because he's amazing.
The linsanity spread across the court like a forest fire, linfusing the players with lincomparable lintensity to win the game, and linfusing linthusiasm among the linsatiable audience.