/ˈjɪəlɪŋ,ˈjəː-/
Noun
1. An animal (especially a sheep, calf, or foal) that is a year old or that is in its second year (Google Dictionary); An animal that is between one and two years old (wiktionary.org).
2. A racehorse that is considered to be one year old until a subsequent January 1st (wiktionary.org).
Adjective
1. Having lived for a year; a year old. (Google Dictionary)