1550s, "a castaway" (rare), from reject (v.). Modern use probably a re-formation of the same word: "thing cast aside as unsatisfactory" (1893); "person considered low-quality and worthless" (1925, from use in militaries).
reject re·ject (rĭ-jěkt')
v. re·ject·ed, re·ject·ing, re·jects
To refuse to accept, submit to, believe, or use something.
To discard as defective or useless; throw away.
To spit out or vomit.
To resist immunologically introduction of a transplanted organ or tissue; fail to accept in one's body.