Very much off-tangent. (Sorry, Bill)

But elenchus makes me think of echida for some odd reason...

Let's see. Why? There's the echidna; and the platypus; and the e-chidna again; and, of course, the missing lenk. That must be it, misspelling excused!

E-Len-Ch-us.

Is this a rhetorical term that came from down under and transmuted itself in flying up to the British Isles?