2.(in numbers, measurements)半；二分之一
He's two and a half now.他现在两岁半了。
I paid two and a half thousand pounds.我付了2,500英镑。
a week and a half一周半
3.half past
(in expressions of time)…点半
I think I got there about four and left about half past.我想我到那儿时大约4点, 离开时大约4点半。
It's half past three.现在3点半。
4.<英,非正式>(half past)半点
We close at half two.我们两点半关门。