It means that the rotation is in the opposite direction.
prograde rotation
Venus and Uranus both have retrograde rotation.
Prograde rotation turns counter clockwise while retrograde rotation turns clockwise. ( As viewed from above the Earth's North Pole.)
Not really; meteors are so insignificant, compared to the mass of the Earth, that it makes precisely zero difference whether the meteor strikes the Earth going with or going against the Earth's rotation. Even a dinosaur killer that would devastate the biosphere isn't going to affect the Earth's rotation.
That is called retrograde rotation.
Out of the four, only Venus. Mercury's rotation is very slow though, compared with its orbital period of the sun.
Venus is the only inner planet that has retrograde rotation; Uranus and Pluto are the only outer planets that have retrograde rotation.
Venus. It spins the other way compared to the other inner planets.
Pluto, like most bodies in the solar system, has a prograde orbit (inclination: ~17° from the ecliptic).Its rotation is retrograde, though (inclined at ~120°).
The planet with the largest (or longest) rotation period is Venus, at 243 Earth days (retrograde, meaning clockwise, instead of counterclockwise like the Earth).
Venus and Uranus have retrograde rotation.
If you mean "retrograde rotation", they are Venus and Uranus.