clenbuterol

noun
clen·​bu·​te·​rol | \ klen-ˈbyü-tə-ˌrȯl, -ˌrōl How to pronounce clenbuterol (audio) \

Medical Definition of clenbuterol

: a sympathomimetic drug used in the form of its hydrochloride C12H18Cl2N2O·HCl especially as a bronchodilator in the treatment of asthma

Note: In the U.S., clenbuterol is only approved for veterinary use to treat airway obstruction in horses. Clenbuterol is also used illicitly by athletes to enhance performance (as by increasing muscle mass and aerobic capacity).