Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
Gold is lethal to the Cybermen, which is why they tried to destroy Voga, the planet of gold in "Revenge of the Cybermen" and why the Fifth Doctor (Peter Davison) used Adric's gold badge for mathematical excellence to kill a Cyberman in "Earthshock".
Source: https://screenrant.com/doctor-who-season-14-rtd-clues-meaning-tigella-kingdom-gold/