Above = • preposition & adverb 1 at a higher level than. The picture of his grandmother is above that of his grandfather.
2 in preference to. I like strawberries above all other fruit.
3 (in printed text) mentioned earlier. See above for the references.
Over = • preposition 1 above so as to cover or protect. Put the plate over the meat.
2 expressing movement or a route across. They travelled over the plains to reach the Rockies.
3 beyond and falling or hanging from. The car went over the edge of the dock.
4 expressing duration. It is over six years since I saw him.
5 more than. That car cost over £20,000.
6 expressing authority or control. The soldier obeys the officers over him.