First-born and Golden-ager

Golden-ager and first-born are semantically related in older person topic. In some cases you can use "Golden-ager" instead a noun phrase "First-born", when it comes to topics like senior.

Golden-ager noun - A person of advanced years.

First-born and golden-ager are semantically related in older person topic. You can use "First-born" instead a noun phrase "Golden-ager", if it concerns topics such as senior.