illegal drug
Defined in 1 dictionary — U.S. Code
United States Code
20 U.S.C. § 1415 — in this subchapter (4 versions over time)
The term "illegal drug" means a controlled substance but does not include a controlled substance that is legally possessed or used under the supervision of a licensed health-care professional or that is legally possessed or used under any other authority under that Act [21 U.S.C. 801 et seq.] or under any other provision of Federal law.