JW:
Reasoning Book, copyright 1985:
Astostasy is abandoning or deserting the worship and service of God, actually a rebellion against Jehovah God. Some apostates profess to know and serve God but reject teachings or requirements set out in his Word. Others claim to believe the Bible but reject Jehovah's organization.
Websters Dictionary, copyright 1998:
a total desertion of or departure from one's religion, cause, party, etc.
If you think about it, almost everyone alive is apostate to something. All the ones that left their original religion to become a JW is apostate. As is anyone who goes from being Democrat to Republican. Or, as in my case, I am apostate because I no longer put my garbage into the recycle bin. Anyone disfellowshipped is also apostate.
When I was in the Borg I thought that all apostates were actively working against the Society (it never entered my mind about them working against Jehovah, only the Society). But by the Websters definition everyone who does not do what they once did, is apostate. Interesting.