insidious

As adjectives the difference between astute and insidious

is that astute is quickly and critically discerning while insidious is producing harm in a stealthy, often gradual, manner.

As adjectives the difference between insidious and deleterious

is that insidious is producing harm in a stealthy, often gradual, manner while deleterious is harmful often in a subtle or unexpected way (as for example deleterious effects, deleterious to health).

As an adjective insidious

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

As a noun duplicity is

intentional deceptiveness; double-dealing.

Insidious is a synonym of sneaking.

As an adjective insidious

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

As a verb sneaking is

.

As a noun sneaking is

the act of one who sneaks.

Insidious is a synonym of clandestine.

As adjectives the difference between insidious and clandestine

is that insidious is producing harm in a stealthy, often gradual, manner while clandestine is done or kept in secret, sometimes to conceal an illicit or improper purpose.

Crafty is a related term of insidious.

As adjectives the difference between crafty and insidious

is that crafty is relating to, or characterized by, craft or skill; dexterous while insidious is producing harm in a stealthy, often gradual, manner.

Sharp is a related term of insidious.

As a proper noun sharp

is .

As an adjective insidious is

producing harm in a stealthy, often gradual, manner.

As adjectives the difference between insidious and incipient

is that insidious is producing harm in a stealthy, often gradual, manner while incipient is in an initial stage; beginning, starting, coming into existence.

As a noun incipient is

beginner.

As adjectives the difference between insidious and sly

is that insidious is producing harm in a stealthy, often gradual, manner while sly is artfully cunning; secretly mischievous; wily.

As an adverb sly is

slyly.

As adjectives the difference between insidious and acute

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

As a noun acute is

an acute accent.

As a verb acute is

to give an acute sound to.