undercover

As adjectives the difference between undercover and undefined

is that undercover is performed or happening in secret while undefined is lacking a definition or value.

As a noun undercover

is a person who works.

As nouns the difference between undercover and beagle

is that undercover is a person who works while beagle is a small short-legged smooth-coated hound, often used for hunting hares often tri-coloured, its friendly disposition makes it suitable as a family pet.

As an adjective undercover

is performed or happening in secret.

As a verb beagle is

to hunt with beagles.

Undercover is a related term of collusive.

As adjectives the difference between undercover and collusive

is that undercover is performed or happening in secret while collusive is secretly acting together for a fraudulent or illegal purpose.

As a noun undercover

is a person who works.

Undercover is a related term of dark.

As adjectives the difference between undercover and dark

is that undercover is performed or happening in secret while dark is having an absolute or (more often) relative lack of light.

As nouns the difference between undercover and dark

is that undercover is a person who works while dark is a complete or (more often) partial absence of light.

Insidious is a synonym of undercover.

As adjectives the difference between insidious and undercover

is that insidious is producing harm in a stealthy, often gradual, manner while undercover is performed or happening in secret.

As a noun undercover is

a person who works.

Undercover is a related term of confidential.

As adjectives the difference between undercover and confidential

is that undercover is performed or happening in secret while confidential is (meant to be) kept secret within a certain circle of persons; not intended to be known publicly.

As a noun undercover

is a person who works.

As an adjective undercover

is performed or happening in secret.

As a noun undercover

is a person who works.

As a verb covet is

to wish for with eagerness; to desire possession of, often enviously.

As adjectives the difference between undercover and underground

is that undercover is performed or happening in secret while underground is below the ground; below the surface of the Earth.

As nouns the difference between undercover and underground

is that undercover is a person who works undercover while underground is an underground railway.

As an adverb underground is

below the ground.

As a verb underground is

to route electricity distribution cables underground.

As a proper noun Underground is

the London Underground.

As nouns the difference between spy and undercover

is that spy is a person who secretly watches and examines the actions of other individuals or organizations and gathers information on them (usually to gain an advantage) while undercover is a person who works undercover.

As a verb spy

is to act as a spy.

As an adjective undercover is

performed or happening in secret.

As adjectives the difference between subversive and undercover

is that subversive is intending to subvert, overturn or undermine a government or authority while undercover is performed or happening in secret.

As nouns the difference between subversive and undercover

is that subversive is a radical supporter of political or social revolution while undercover is a person who works.