关于bicycle单词

是bi-cycle,查英英翻译就是:
a wheeled vehicle that has two wheels and is moved by foot pedals
“bi-”作前缀有“成双,成对”的意思,类似的三轮车的说法可以用tri-cycle.
小学时的课本应该都一样的吧?
bike本身就是单车的意思,不能后面加cycle