- The state of being a colt; the youth of a (male) horse.
1876, Various, Lippincott's Magazine of Popular Literature and Science:
- Their ruddy faces and somewhat cumbrous forms belong to the animal period of life that links together boyhood, colthood and calfhood.
1917, B. M. Bower, The Lookout Man:
- She had a vague notion that all horses nowadays were trained from their colthood to buck--whatever that was.
1922, Max Brand, Alcatraz:
- In the old days of his colthood, a barelegged boy used to come into the pasture and jump on his bare back.