To recuperate is to get something back that you have lost — could be good health, or money lost in a bad investment. When you recuperate, you heal and recover.
Recuperate comes from the Latin word recuperare “to take back,” so when you recuperate you gain something back that was yours before — health or money. Recuperate is usually something people do after an illness. If you break your knee playing rugby in college, you might go home to recuperate. If you don't want to sound fancy, just say you're recovering. It also means to get money back, so you can also try to recuperate your losses by staying in the poker game.