Extendable rhymes with:
amendable, commendable, dependable, expendable, spendable, amendable, commendable, dependable, expandable, expendable, mandible, nonrefundable, refundable, spendable, understandable
amendable, commendable, dependable, expendable, spendable, amendable, commendable, dependable, expandable, expendable, mandible, nonrefundable, refundable, spendable, understandable