|a fool or simpleton; ninny.|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
semipermeable sem·i·per·me·a·ble (sěm'ē-pûr'mē-ə-bəl, sěm'ī-)
Allowing passage of certain, especially small, molecules or ions but acting as a barrier to others. Used of biological and synthetic membranes.