plural spies
1
: a person who tries secretly to get information about a country or organization for another country or organization
He was a spy for the CIA.
a Cold War spy
—often used before another nouna spy novel/thriller [=a novel/thriller about spies]
a spy camera/plane [=a camera/plane used for spying]
2
: someone who secretly watches the movement or actions of other people
My coworker is a spy for the boss.
the neighborhood spy
spies; spied; spying
1
: to try secretly to get information about a country, organization, etc. : to act as a spy
They were accused of spying for a foreign government.
—often + onThey were accused of spying on a rival company.
2
: to see or notice (someone or something)
She spied [=caught sight of] a friend in the crowd.
Cite this Entry
“Spy.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/spy. Accessed 4 Apr. 2026.
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