And the circle is closed by "tipper" which also has the t-p-r pattern. Actually "dildurn" sounds as if it should refer to the tipper than to the drum ;-).

Imagine the confusion a few centuries from now when they try to figure all this out.

Greg is right when he says we need some expertise, there's an awful lot of speculative or outright spurious etymology out there on the web. When I discovered Indian music I wrongly assumed on the basis of an apparent etymological connection that the tanpura was the drums (actually tabla), not a stringed accompanying instrument.