oil derived from the leaves of the peppermint plant Mentha × piperita, which is used for a number of purposes.

(ornithology) The light oil composed of neutral dietary lipids found in the proventriculus of birds in the order Procellariiformes.

(petroleum industry, slang, US, dated) A microfossil, particularly a foraminiferan.

(rare, television) An amoral drama focussing on corporate and domestic struggles, the lead character being a businessman (or businesswoman) fixated on pursuing a resource by any means necessary.

plural of oil opera

Gas for lighting or heating, made by distilling oil in closed retorts.

An oil expressed from the nuts of the beech tree.

oil of spike

(archaic) crude petroleum

Oil made from coquito nuts.