insidious

As adjectives the difference between insidious and tragic

is that insidious is producing harm in a stealthy, often gradual, manner while tragic is causing great sadness or suffering.

As a noun tragic is

a writer of tragedy.

In nonstandard|lang=en terms the difference between insidious and insidious

is that insidious is (nonstandard) treacherous while insidious is (nonstandard) treacherous.

As adjectives the difference between insidious and insidious

is that insidious is producing harm in a stealthy, often gradual, manner while insidious is producing harm in a stealthy, often gradual, manner.

As adjectives the difference between insidious and malicious

is that insidious is producing harm in a stealthy, often gradual, manner while malicious is of, pertaining to, or as a result of malice or spite.

As adjectives the difference between insidious and precarious

is that insidious is producing harm in a stealthy, often gradual, manner while precarious is (comparable) dangerously insecure or unstable; perilous or precarious can be (dentistry) relating to incipient caries.

As adjectives the difference between insidious and chronic

is that insidious is producing harm in a stealthy, often gradual, manner while chronic is of a problem, that continues over an extended period of time.

As a noun chronic is

marijuana, typically of high quality.

As adjectives the difference between insidious and tricky

is that insidious is producing harm in a stealthy, often gradual, manner while tricky is hard to deal with, complicated.

As adjectives the difference between imperceptible and insidious

is that imperceptible is not perceptible, not detectable, too small in magnitude to be observed while insidious is producing harm in a stealthy, often gradual, manner.

As adjectives the difference between insidious and sick

is that insidious is producing harm in a stealthy, often gradual, manner while sick is in poor health.

As a noun sick is

sick people in general as a group.

As a verb sick is

to vomit or sick can be (rare).

As an adjective insidious

is producing harm in a stealthy, often gradual, manner.

As a verb undermine is

to dig underneath (something), to make a passage or for destructive or military purposes; to sap.

As adjectives the difference between insidious and disingenuous

is that insidious is producing harm in a stealthy, often gradual, manner while disingenuous is not noble; unbecoming true honor or dignity; mean; unworthy; fake or deceptive.