a.head

ahead的音标和读音：
DJ音标发音： [əˈhed]
KK音标发音： [əˈhɛd]

ahead的词性：
adv.（副词）

1. At or to the front or head.
在前面，在前头

2. In advance; before:
预先；在…之前：

Pay ahead, and you'll receive a discount.
若预先付款，你便可以享受折扣

3. In or into the future; for the future:
在将来；为将来：

planned ahead.
计划未来

4. In an advanced position or a configuration registering the future:
向前，朝前：处于前列的位置或指示未来的方位：

Set the clock ahead.
把时钟拨快

5. At or to a different time; earlier or later:
或早或晚：在不同的时间；提前或推迟：

moved the appointment ahead, from Tuesday to Monday.
把约会从星期二提前到星期一

6. In a forward direction; onward:
朝前；向前：

The train moved ahead slowly.
火车缓缓向前移动

7. In the prescribed direction or sequence for normal use:
按常规地：为得到正常的使用而朝向规定的方向或顺序：

You won't hear anything unless you roll the tape ahead.
除非你把录音带往前转，否则你是不会听到任何东西的

8. In or into a more advantageous position:
更有利：处于更有利的地位：

wanted to get ahead in life.
想出人头地

9. To be winning or in a superior position:
领先，占优势：

The home team was ahead in the second period. Your company is ahead in developing the new technology.
主队在第二阶段的比赛中处于领先。你们的公司在发展新科技方面处于领先地位