Hobnail may refer to:

In footwear

• A short nail with a thick head: used to increase the durability of boot soles.
• Hobnailed boots have been used since antiquity for inexpensive durable footwear, often by workmen and the military. They have hobnails, usually installed in a regular pattern over the whole sole. They also usually have an iron horseshoe-shaped insert to strengthen the heel. They provide traction on soft or rocky ground, but they tend to be skiddy on smooth hard artificial surfaces.

Other uses

• A pattern of glassware: (sometime called Fenton Hobnail) where the body of the piece has a regular array of bumps, as if finished with glass hobnails.
• A musical band in New Zealand: called Hobnail Boots.
• A popular song from 1907, performed by Billy Williams (http://billy_williams_oz.tripod.com/recordings.htm).
• "Hobnailed liver" is medical jargon for cirrhosis of the liver.