To have an alternative plan or resource available in case the current one fails.

अतिरिक्त योजना या संसाधन होना

English Usage: She decided to learn graphic design so she would have a second string to her bow.

Hindi Usage: उसने ग्राफिक डिजाइन सीखने का फैसला किया ताकि उसके पास दूसरा उपाय हो।