yearling

yearling
/ˈjɪəlɪŋ; `jɪrlɪŋ/ n
animal, esp a horse, between one and two years old 一岁至两岁的动物（尤指马）
    a race for yearlings 一两岁小马的赛马
    [attrib 作定语]
a yearling filly 一两岁的小雌马.

牛津英汉双解词典