| a chattering or flighty, light-headed person. |
| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |
insidious in·sid·i·ous (ĭn-sĭd'ē-əs)
adj.
Being a disease that progresses with few or no symptoms to indicate its gravity.