...a glum, downcast expression.是什么意思？

...a glum, downcast expression.

忧郁、沮丧的表情

glum

adj. 闷闷不乐的，忧郁的，阴沉的；

例句
She was very glum and was obviously missing her children.
她郁郁寡欢，显然在惦念自己的孩子们。

downcast

adj. 情绪低落的，向下的，颓靡；

例句
Barbara looked increasingly downcast as defeat loomed.
当败象已呈时，芭芭拉看上去越来越沮丧。

expression

n. 表现，表示，表达，表情，脸色，态度，腔调，声调，[数]式，符号，词句，语句，措辞，说法；

例句
He mistakenly ascribes the expression 'survival of the fittest' to Charles Darwin.
他错误地认为“适者生存”是查尔斯·达尔文说的。