1
- denoting the front, forward, or upper part or end of a specified thing表示“前部”, “向前”, “顶部”, “端头”：
spearhead
masthead.
2
- in nouns used informally to express disparagement of a person（用于名词中, 表示鄙视）：
airhead
dumbhead.
3
- in nouns used informally to denote an addict or habitual user of a specified drug〈非正式〉表示“所指毒品的成瘾者（或常用者）”：
crackhead.