The Collaborative International Dictionary of English v.0.48:

Lincture \Linc"ture\ (l[i^][ng]k"t[-u]r; 135), Linctus
\Linc"tus\ (l[i^][ng]k"t[u^]s), n. [L. lingere, linctum, to
   lick.]
   Medicine taken by licking with the tongue.
   [1913 Webster]