arranged, considered, or done in order of application or arrival, as for purposes of service: orders filled on a first-come basis.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for first-come
Historical Examples of first-come
This is enough to prove that he was not the first-come ignoramus or madman that some people then liked to think him.The Liberation of Italy
Countess Evelyn Martinengo-Cesaresco