When an action is spoken of as intrinsically evil the meaning is that the action itself is wrong by its nature, regardless of the end intended.
To curse God, or strangling a baby deliberately termination a pregnance are actions which are evil in themselves. Artificial contraception is called intrinsically evil because it interferes directly with the potential divine plan. It is necessary to remember, however, that an act which is evil in itself still may not be a bad as one whichi is even graver by reason of its consequences, or the intention behind it.
Thus contraception is always wrong by nature. Firing a gun can be morally neutral or even a good thing. But to fire a gun into a crowded schoolyard is a graver sin than a contraceptive act.
English has more words than Latin which is the primary language of moral theology, and it does happen that phrases in English take on a coloring which is not found in the original.