Wikipedia
SIBOR stands for Singapore Interbank Offered Rate and is a daily reference rate based on the interest rates at which banks offer to lend unsecured funds to other banks in the Singapore wholesale money market (or interbank market). It is similar to the widely used LIBOR ( London Interbank Offered Rate), and Euribor (Euro Interbank Offered Rate). Using SIBOR is more common in the Asian region and set by the Association of Banks in Singapore (ABS).
SIBOR comes in 1-, 3-, 6- , or 12-month tenure. SIBOR of the month is used in the month when the letter of acceptance is signed. At the end of the tenure, the borrowing bank returns the borrowed fund to the lending bank.
Many floating rate mortgages in the country are pegged to SIBOR due to its transparency.