1. Adjective.  likely to be affected by something.
  2. Adjective.  easily influenced or tricked; credulous.
  3. Adjective.  (medicine) especially sensitive, especially to a stimulus.
  4. Noun.  (epidemiology) A person who is vulnerable to being infected by a certain disease.

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.