I believe that it means "I create as I think". If one has come to the conclusion, as many ancients had, that we create our reality through our thought, feelings, beliefs and expectations, then a one can see the modern connection with magic.
Abracadabra is a word that has been and is associated with magical incantations meant for various purposes. The word is now mostly seen as a word for entertainment used by stage magicians. The use of this word in the past, however, was much more serious. It was used in incantations for curing various inflammations and fevers. There are many different theories in the origin of this word. One such theory suggests that the word is a derivative of an Aramaic phrase that means "I create as I speak". Another Aramaic word that is said to be the source from which Abracadabra is derived is the word for the phrase "disappear like this word". It is believed to have been a phrase in an incantation to eliminate illnesses. There are many possible origins for this word and it has been around for a very long time. The only thing that is known for sure is that whatever its origin that this word is related to the concept of some type of magical force.