Is there any attested etymology for this word or can anyone otherwise attempt to break down its compositional logic for me please?
On the face of it, 是指 looks structurally similar to 是说. However, the 是 in 是指 lacks any emphatic or contrastive or concessive sense; in fact, 是指 is frequently used in the most declarative of contexts, such as dictionary definitions and the like.
My intuition tells me this word must have resulted from the lexicalisation of a longer construction: something like X+是+指(=针对)Y+的意思 turning into X+是指+Y.
I would be grateful for any other suggestion.