Like all JW propaganda the question is flawed and skewed towards the interests of the writer asking it.
The question has meaning only for JWs since they are to my limited knowledge the only group who bother about the whimsical issue of "true worship". (Adventists may?)
Why do they harp on this subject? Because they proceed on the basis of having dualistic worlds of Jehovah's and Satans. If you worship Big J, or so they make out, you are doing true worship and all others by default are guilty of "false worship".
True worship is only construed as a religious item because of the Hebrew prophet's condemnation of polytheism, calling it false worship. In its mind manipulation programme the Watchtower is ever eager to employ the cherished slogans of irrelevant Iron Age prophets.
If you step out of the JW tar-pit and think more clearly, the notion of true worship is a catch phrase which only a cult would dare to use, it insults all those of religions who are not JWs. Apart from that there is no realistic definition because worship is not qualified by its "trueness," It is a convention to respect that a worshipper worships with sincerity of heart not with the technical approval of a particular religious authority.