Early and Underivative

Early adjective - Relating to or occurring near the beginning of a process, series, or time period.

Underivative and early are semantically related In some cases you can use "Underivative" instead an adjective "Early".

Underivative adjective - Not derivative or imitative.

Early and underivative are semantically related in ancient topic. Sometimes you can use "Early" instead an adjective "Underivative", if it concerns topics such as earliest.