ruthless

As adjectives the difference between brash and ruthless

is that brash is impetuous or rash or brash can be (us|colloquial|dated) brittle, as wood or vegetables while ruthless is without pity or compassion; cruel, pitiless.

As a noun brash

is leaf litter of small leaves and little twigs as found under a hedge.

As adjectives the difference between volatile and ruthless

is that volatile is (physics) evaporating or vaporizing readily under normal conditions while ruthless is without pity or compassion; cruel, pitiless.

Ruthless is a related term of demoniac.

As adjectives the difference between ruthless and demoniac

is that ruthless is without pity or compassion; cruel, pitiless while demoniac is possessed or controlled by a demon.

As a noun demoniac is

someone who is possessed by a demon.

Ruthless is a related term of murderous.

As adjectives the difference between ruthless and murderous

is that ruthless is without pity or compassion; cruel, pitiless while murderous is intending, or likely to commit murder; bloodthirsty or homicidal.

Ruthless is a related term of satanic.

As adjectives the difference between ruthless and satanic

is that ruthless is without pity or compassion; cruel, pitiless while satanic is satanic.

As adjectives the difference between heinous and ruthless

is that heinous is totally reprehensible while ruthless is without pity or compassion; cruel, pitiless.

As adjectives the difference between evil and ruthless

is that evil is intending to harm; malevolent while ruthless is without pity or compassion; cruel, pitiless.

As a noun evil

is moral badness; wickedness; malevolence; the forces or behaviors that are the opposite or enemy of good.

Ruthless is a related term of unmerciful.

As adjectives the difference between ruthless and unmerciful

is that ruthless is without pity or compassion; cruel, pitiless while unmerciful is not showing mercy.

Inhumane is a related term of ruthless.

As adjectives the difference between inhumane and ruthless

is that inhumane is lacking pity or compassion for misery and suffering; cruel, unkind, not humane while ruthless is without pity or compassion; cruel, pitiless.

Bestial is a related term of ruthless.

As adjectives the difference between bestial and ruthless

is that bestial is beast-like while ruthless is without pity or compassion; cruel, pitiless.