His cool green eyes became positively frosty.是什么意思？

His cool green eyes became positively frosty.

他冷冷的绿眼睛好像结了一层霜。

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。

cool

adj. 冷静的，凉爽的，一流的，孤傲冷漠的；vt.& vi. （使）变凉，（使）冷静，使冷却，变凉，冷却，平息；n. 凉气，凉快的地方，凉爽，凉爽的空气；

例句
On first acquaintance she is cool and slightly distant.
初次相见时她表现冷淡并有点爱搭不理。

green

adj. 绿色的，未熟的，青春的，未成熟的，主张保护环境的；n. 绿色蔬菜，绿色的衣服，植物；vi. 绿化，使重视环境保护问题；

例句
The sun has already set, leaving the sky afire with orange and green light.
太阳已经落山，但天空中还映照着如火般橙绿相间的余晖。

eyes

n. 眼睛( eye的名词复数 )，视力，眼状物，风纪扣扣

例句
Her voice is passionate. Her eyes are ablaze.
她声音激昂，目光如火。

became

v. 变为，成为（ become的过去式 ）；

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。

positively

adv. 明确地，断然地，肯定地；

例句
The bathroom, with its ancient facilities, is positively arctic.
该浴室设备陈旧，肯定非常寒冷。

frosty

adj. 严寒的，霜冻的，冷淡的，灰白的；

例句
...sharp, frosty nights.
寒冷刺骨的夜晚