spy onsomeone/something
phrasal verbwithspyverbuk/spaɪ/us/spaɪ/
C2
towatchsomeone or somethingsecretly, often inordertodiscoverinformationabout him, her, or it:
He wasspyingon her through thekeyhole.
International relations: spying and espionage
- agent
- agent provocateur
- anti-bug
- counter-espionage
- insider
- intel
- intelligence
- MI5
- MI6
- scout
- shadow
- sleuthing
- snoop
- spook
- spy
- superspy
- tail
- tap
- the CIA
- tradecraft