- If you are looking for the beverage from the re-imagining, it is spelled ambrosia.
Ambrosa (note the spelling) is an expensive alcoholic intoxicant, typically green in color.
Its rarity makes it valuable amongst the survivors; Starbuck imagined being rich after finding many storage bins filled with ambrosa on Proteus. Were it not for the Cylon attack on Proteus, he would have become quite wealthy. (The Long Patrol)