varenicline

Etymology
From.

Noun

 * 1)  A drug taken orally in the form of its tartrate C13H13N3·C4H6O6 as an aid to stop smoking. It binds to nicotinic cell receptors to block the activity of nicotine while also acting as an agonist to reduce nicotine cravings and withdrawal symptoms. It is marketed under the trademark Chantix.