Ac is the vowel a (ah)
Anglo-Saxon Rune Poem (from ragweedforge.com)
The oak fattens the flesh of pigs for the children of men.
Often it traverses the gannet’s bath,and the ocean proves whether the oak keeps faithin honourable fashion.
All I can say about Ac reversed today is that it seems to be rune that appears frequently when I am physicall, mentally, or spiritually tired from activities of the previous day. Ac indicates that my energies are low, and that I lack stamina, fortitude and the power to endure.