In Greece we call it "Agourelaio" which is actually the extra virgin olive oil that is produced from unripe green olives.
The most well known & probable term is "Early Harvest" and refers to the olive oil produced from green olives that have been harvested early from late September to mid-late October (depending on the variety, the region, the climatic conditions, etc.).
Its color is intense green and has a more bitter and spicy taste due to its high content of phenolic compounds. To take advantage of its high nutritional value but also its unique taste to the fullest, one should consume it within a maximum of 2-3 months.