Toxic metallic element (8)

I believe the answer is:

antimony

(Other definitions for antimony that I've seen before include "Bluish-white element, symbol Sb" , "Semimetallic element" , "Toxic metallic element used in semiconductors" , "My nation (anag) - metallic element" , "One element" .)

I've seen this clue in The Times.

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.