Originally Posted by Izannah
Child abandonment can be described as follows: A parent's failure to provide any financial assistance to or communicate with his or her child over a period of time. When this happens, a court may deem the child abandoned by that parent and order that person's parental rights terminated. Abandonment also describes situations in which a child is physically abandoned -- for example, left on a doorstep, delivered to a hospital or put in a trash can. Physically abandoned children are usually placed in orphanages and made available for adoption.
So TECHNICALLY, yes, this could be considered child abandonment, or at least an abandonment of his parental responsibilities. What will matter the most in this are the laws in your area regarding such matters.
The previous posters are correct in that you need to go back to court and report what has happened and let the court either modify it's previous order or issue a new order for support and custody.