Rapeseed (Brassica napus subsp. napus), also known as rape and oilseed rape and canola, is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed, which naturally contains appreciable amounts of mildly toxic erucic acid.[2] The term "canola" denotes a group of rapeseed cultivars that were bred to have very low levels of erucic acid and which are especially prized for use as human and animal food. Rapeseed is the third-largest source of vegetable oil and the second-largest source of protein meal in the world.[3][4]

Brassica napus subsp. napus is the proper name. Everything else is slang and not worth arguing about.

We call it Sunflower Oil

We call it Rapeseed Oil

Not Rape Seed Oil