IPA: /ˌriːɪnˈfɛkt/
KK: /riˈɪnˌfɛkt/
To cause someone or something to become infected again after they have already been infected.
After recovering from the flu, she was worried she might reinfect herself by not taking precautions.
Past: reinfected
Past Participle: reinfected
Reinfect → It is formed from "re-" (meaning again) and "infect" (from Latin "inficere", meaning to taint or stain). The word "reinfect" means to infect again or to taint once more.
Think of being infected 'again' ('re-') after having been infected before — that's what reinfect means.