noun
reserved-seat ticket
A ticket that guarantees a specific seat, commonly used for trains, planes, theaters, and events.
新幹線に乗る前に、座席指定券を買っておいたほうがいいですよ。
You should buy a reserved-seat ticket before boarding the Shinkansen.
Compound of 座席 (zaseki, 'seat'), 指定 (shitei, 'designation'), and 券 (ken, 'ticket').