The term 'SOURCE OF A FRAGRANT OIL' can be answered by two crossword solutions: NARD (4 letters) and ORRIS (5 letters). Nard is an aromatic oil derived from the root of the Nardostachys jatamansi plant, which is native to the Himalayas. ORRIS is a fragrant oil obtained from the rhizomes of the Iris germanica plant, which is native to Europe and North Africa. Both oils are used in perfumes and cosmetics.