convertible
1. con.vert.ible \k*n-'v*rt-*-b*l\ \-ble-\ aj 1: capable of being converted
2: having a top that may be lowered or removed {~ coupe} 3: capable of
being exchanged without restriction for gold or currency of another kind -
con.vert.ible.ness n
2. convertible n : something convertible; esp : a convertible automobile
Webster's English Dictionary