Origins
English borrowed the same Latin word twice, centuries apart, and kept both copies. Recover comes from Old French recovrer, itself from Latin recuperāre — 'to get back, to regain'. Recuperate arrived later, borrowed directly from the Latin in the 16th century. Both mean roughly the same thing, but recover wears French clothing while recuperate kept its Roman dress.
The Latin recuperāre combined re- ('back') with a form related to capere ('to take'). To recover is to take something back — health, property, composure, ground.
The word entered English through Anglo-French legal language in the 14th century. Its earliest English uses were courtroom terms: to recover damages, to recover a debt by judgement. The medical sense — recovering from illness — ran in parallel, treating health as property that had been temporarily lost.
Figurative Development
This metaphor remains alive. We speak of recovery as though wellness were a possession misplaced during illness and found again afterward. The legal and medical senses share the same underlying logic: something that belonged to you was taken, and now you are getting it back.
The breadth of recover mirrors its Latin ancestor. Romans used recuperāre for regaining health, recapturing cities, and reclaiming debts — the same three domains the English word still covers.