Especially from roses -- so attar of rose is rose-oil. Can also mean a perfume made from such oils, and also any (typically heavy) (usually botanical) fragrance in general. Alternate forms include atar and ottar, at least according to dictionaries, but I confess I've never seen it except as attar. Borrowed in the 1790s from Persian 'atar, short for 'atar-gūl, attar of roses, from ʿatara, to smell sweet, from iṭr, fragrance, from Arabic roots. Yes, I know, those should be in Persian script, but the smell was too overpowering to work out how to include those. For a usage, a recipe:
Attar of roses is made in the following manner: -- On 40 pounds of roses are poured 60 pounds of water, and they are then distilled over a slow fire, and 30 pounds of rose water obtained.Learn something every day.