'carriage bolt' definitions:

Definition of 'carriage bolt'

From: WordNet
noun
A roundheaded bolt for timber; threaded along part of the shank; inserted into holes already drilled

Definition of 'carriage bolt'

From: GCIDE
  • carriage bolt \carriage bolt\ n. a type of bolt threaded only at the end opposite the head, used mostly for fastening pieces of timber together, and inserted into pre-drilled holes. [PJC]