from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Being such that attack, seizure, or capture is possible; vulnerable or assailable: a pregnable fortress.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. vulnerable to attack
from the GNU version of the Collaborative International Dictionary of English
- adj. Capable of being entered, taken, or captured; expugnable.
from The Century Dictionary and Cyclopedia
- Capable of being taken or won by force; expugnable.
- Capable of being moved, impressed, or convinced.
Middle English preignable, pregnabul, from Old French prenable, pregnauble, from prendre, to grasp, from Latin prehendere, prēndere; see ghend- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)