noun
motorcycle license
Refers specifically to a license for operating a motorcycle (二輪車). In Japan, this is a distinct category of driver's license.
彼は二輪免許を取って、バイクで通勤している。
He got his motorcycle license and commutes by bike.
普通免許 is a standard car driver's license, while 二輪免許 is specifically for motorcycles.
Compound of 二輪 (two wheels) and 免許 (license).