Treachery, Duplicity
This page is the CodyCross answer for the clue below from Physics, Group 1888, Puzzle 3 (Magnetic Field).
Question is: Treachery, Duplicity
and the answer is: PERFIDY
Word Meaning:
PERFIDY — A state or act of violating faith or allegiance; violation of a promise or vow, or of trust.
Definitions from Wiktionary.