1. like crazy - Adverb
2. like crazy - Phrase
(informal) with great speed or effort or intensity; used for emphasis
Source: WordNetNewspaper readership is declining like crazy. In fact, there's a good chance that nobody is reading my column. Dave Barry
He makes me laugh like crazy. We're still kids inside. We're mature and responsible when it comes to business, but we know how to have fun. Gloria Estefan
The thing about smart people is that they seem like crazy people to dumb people. Stephen Hawking
It was January and snowing like crazy. It was tough; the food was terrible. Eighteen months of my life for nothing? I thought my own dreams were more important. Tarkan
Just keep going like crazy and look back when it's over. Otherwise you just get confused. Cliff Burton
I tip like crazy. They'll remember me. Celebrity can be expensive. Phil Donahue