How Well Do You Know English Slang?
early 15c., "rejected as worthless," from Late Latin reprobatus, past participle of reprobare "disapprove, reject, condemn," from Latin re- "opposite of, reversal of previous condition" (see re-) + probare "prove to be worthy" (see probate (n.)). Earliest form of the word in English was a verb, meaning "to disapprove" (early 15c.).
1540s, "one rejected by God," from reprobate (adj.). Sense of "abandoned or unprincipled person" is from 1590s.
that which is rejected on account of its own worthlessness (Jer. 6:30; Heb. 6:8; Gr. adokimos, "rejected"). This word is also used with reference to persons cast away or rejected because they have failed to make use of opportunities offered them (1 Cor. 9:27; 2 Cor. 13:5-7).