The American Heritage® Dictionary of the English Language, 4th Edition
n. The quality or state of being pertinacious: "Again and again ... with the inexorable pertinacity of a child ... did he renew his efforts” ( Nathaniel Hawthorne).
n. The state or characteristic of being pertinacious.
the GNU version of the Collaborative International Dictionary of English
n. The quality or state of being pertinacious; obstinacy; perseverance; persistency.
The Century Dictionary and Cyclopedia
n. The character of being pertinacious; resoulute or unyieding adherence, as to an opinion, purpose, design, course of action, etc.; persistency; obstinacy; resoluteness: as, to cling with pertinacity to one's purpose.
n.Synonyms See pertinacious.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. persistent determination
Word Usage
"The forward cylinder was depending on that unknown force men call the pertinacity of materials, which now and then balances that other heartbreaking power, the perversity of inanimate things."