Yearling/ˈjɪrlɪŋ/ Definition 1 of 2Pro Tip 1/3Animal Age Refer specifically to animals in their second year of life, not older or younger ones. The shepherd moved the yearlings to a new pasture. Pro Tip 2/3Growing Stage 'Yearling' suggests the animal is still growing and not fully mature. Yearling horses are not yet strong enough for long rides. Pro Tip 3/3Breeding Term Often used in the context of farming or animal husbandry to describe young livestock. The yearling bulls will be auctioned off next month.