Age-old and Primaeval

Age-old adjective - Dating or surviving from the distant past.

Primaeval and age-old are semantically related. In some cases you can use "Primaeval" instead an adjective phrase "Age-old".

Primaeval adjective - Having existed from the beginning; in an earliest or original stage or state.

Age-old and primaeval are semantically related. Sometimes you can use "Age-old" instead an adjective "Primaeval".