His laugh-a-minute image is just a front to hide his deep unhappiness.是什么意思？

His laugh-a-minute image is just a front to hide his deep unhappiness.

他滑稽可笑的形象只是用来掩饰内心深处痛苦的假面具。

his

pron. (he的所有格)他的，(he的物主代词)他的东西；det. 属于他的，用于名词前，自己的，指某人的，上帝的；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

image

n. 影像，肖像，概念，意向，镜像，映像；

例句
The image of the fox as a pest is grossly exaggerated in anecdote and folklore.
狐狸的害人精形象在传闻和民间故事中遭到严重的夸大。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

just

adv. 刚才，仅仅，只是，正好，刚要；adj. 公正的，合理的，恰当的，合法的，正确的；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。

front

n. 前面，正面，身体前部，前线；adj. 前面的，正面的，舌前的；v. 面向，在…前面，用…作正面，领

例句
I peered ahead through the front screen...
我透过面前的挡风玻璃凝视前方。

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

hide

vt. 隐藏，躲避，隐匿，躲藏，遮蔽，覆盖；vi. 隐瞒，遮住，遮挡，掩盖；n. 兽皮，<口>生命，<口>人的皮肤，（观看野生动物的）隐蔽处；

例句
Their mother was trying to hide her two blacked eyes.
他们的母亲想遮住自己被打青的双眼。

deep

adj. 深的，深远的，深奥，重大的，深刻的，强烈的，痛切的，深厚的；n. 深处，深渊；adv. 深深地，深入地；

例句
When I arose from the chair, my father and Eleanor's father were in deep conversation...
当我从椅子上站起来时，我父亲和埃莉诺的父亲谈兴正浓。

unhappiness

n. 不快，痛苦，不幸；

例句
He could not bear to lay too much responsibility for the unhappiness of his later years on his own shoulders...
为自己晚景凄凉承担这么多责任，他接受不了。