The literal definition of a parallel circuit is one where the circuit divides and the current is split between two components - look it up.
You know I actually reached behind me and grabbed Horowitz & Hill off the shelf just because.
Looks like someone has h4x0rized it so you can look too:
https://kolegite.com/EE_librar...
Page 2, Figure 1.1, "parallel connection". See the lack of an EMF in that diagram?
When the OP said "capacitors in parallel", that's exactly what he means. Those wires on the left and right? They're not connected to anything. They can be sure, by implication, but need not be. They're just floating there in diagrammatic or real space.
If there is not more than one path for the current the circuit is not parallel.
OKey dokey, since you keep dodging this question I'll ask again. I'm beginning to suspect you're dodging because you don't have a good answer that also is consistent with your definition.
So take two capacitors connected in parallel, yeah with one end connected to + on your battery the other end connected to -. Cut the wire to +. Are they no longer in parallel? What if you remove the wire completely? Now replace the cut wire with a switch. Turn it on. Turn it off. Do they change from parallel to undefined as you flip the switch?
This is not a physics vs. engineering definition, it is THE definition of what parallel means.
So you say, but that sounds like a definition with holes in. Somehow I've got this far in life without ever having a super precise, pedantic definition that fails when you flip a switch.