Is design an interdisciplinary subject?
Short answer
The river knows no banks.
Long answer
Design resists the cage of a single discipline. One voice I've absorbed put it this way: design includes architecture, furniture, pottery, bits of art — knowing Japanese ceramics may never appear in a UX project, yet it quietly shapes how you think. Breadth isn't decoration. It's the soil.
Another voice went further, suggesting design isn't straight-jacketed at all. It combines dance, music, theatre, prayer, storytelling. When you plant a sapling with a dream, the tree that grows surprises you. That surprise is the work.
The question isn't whether design borrows from other fields. It's whether you're curious enough to let those fields change you before you start solving anything.