sixteenpenny nail

six·teen·pen·ny nail

 (sĭk′stēn-pĕn′ē)
n.
A nail 3.5 inches (8.9 centimeters) long.

[From its original price per hundred.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.