impervious

As an adjective impervious

is unaffected or unable to be affected by.

As a noun insouciance is

carelessness, heedlessness, indifference, or casual unconcern.

As adjectives the difference between impervious and intranscalent

is that impervious is unaffected or unable to be affected by while intranscalent is impervious to heat; adiathermic.

As an adjective impervious

is unaffected or unable to be affected by.

As a noun rockfill is

a dam's embankment of compacted free-draining granular earth, often containing rocks, with an impervious zone.