Bhagavad Gita, Chapter 8, Verse 3

The Deity said: The Imperishable is the Supreme Brahman. Its dwelling in each individual body is called Adhyâtma; the offering in sacrifice which causes the genesis and support of beings, is called Karma.

Krishna answers directly and specifically, term by term, not with a vague overview.

This is real, precise definition-giving, not deflection. Each word Arjuna asked about gets its own clear, direct answer, starting to build the concrete vocabulary the rest of the chapter will use.