Wiktionary
a. 1 Of or relating to an immigrant or his family 2 Of or relating to the initial version of a class of products
Usage examples of "first-generation".
They all looked to Deckard like first-generation Mars natives, some of the younger ones possibly second-gen, the children and grandchildren of the Earth-born emigrants who’d gotten this far and had then given up on getting all the way to the stars.
Companion galaxies are found to be systematically redshifted with respect to the central galaxy, indicating them to be first-generation descendants.
But where all parts of the first-generation Veritechs participated in reconfiguration, the augmentation packs and energy generators of the Armored Alphas (essential for the space and ground missions that typified the Expeditionary Force) remained intact during the process.