Simple substance (7)

I believe the answer is:

element

(Other definitions for element that I've seen before include "Operative part of an electric kettle" , "Eg copper" , "Constituent of universe" , "Constituent -- habitat" , "eg Fire, air" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.