Salicylic a. : Pertaining to, derived from, or designating, an acid formerly obtained by fusing salicin with potassium hydroxide, and now made in large quantities from phenol (carbolic acid) by the action of carbon dioxide on heated sodium phenolate. It is a white crystalline substance. It is used as an antiseptic, and in its salts in the treatment of rheumatism. Called also hydroxybenzoic acid.

Example:
How much Salicylic acid is in aspirin?

Taxonomy
salicylic acid, compounds, Plants, hearing loss, bark, Aspirin, fever, Plant hormone, acetylsalicylic acid, free encyclopedia, salicylate, zinc, acids, injection, systemic, products, BHA, History.

Defination from the web:
Salicylic acid (from the Latin word for the willow tree, Salix, from whose bark it can be obtained) is a beta hydroxy acid (BHA) with the formula ... Acidification of the product with sulfuric acid gives salicylic acid: ...