Originally Posted by
Shurrikhan
I mean... not really?
Druid (from Celtic draoidh - roughly "true/truth know-er") historically just referred to a(ny) magician/sorcerer/witch/warlock/etc.
It'd be a more vague term than even Conjurer if not for it DnD just happening to use Mage (wisdom / wise-person / sage / seer) as the generic word for a magic-user and then an almost identical term for magic user ("true knower") to instead be somehow restricted to nature-based magics.
A conjurer is one who calls (jur) forces/aspects together (con-) or does/forms something from their being put together, be that from between multiple worlds (the 'real' world and hell, for instance, wherein they'd be demon-summoners) or multiple layers of the same world (the manifest and the underlying, the material and the elemental, etc.).
Just because DnD decided, rather arbitrarily, to make Conjury refer only to the creation of new units, and then split the otherwise identical meaning Voke into offensive (Evocation) and self-buffing (Invocation) spells, doesn't mean all further references are beholden to that.