According to the Oxford English Dictionary an Apostate is "a person who renounces a religious or political belief or principle." (Interestingly, the word is derived from the Greek apostatēs, which was a term used to designate a runaway slave.)
The fact is that any JW who wasn't born into a Jehovah's Witness family, and who practiced a different faith before their conversation, is now an apostate by definition! My mother was raised a Methodist, not a JW. Thus, the moment she decided to abandon her childhood faith and get baptized, she became an apostate. There are so many JWs with similar backgrounds and any JW who calls you an apostate should be reminded of this fact. In fact, an apostate who criticizes others for being apostates is also a hypocrite and we all know how Jesus felt about hypocrisy.