*blue¹/blu; bluː/ adj 1 having the colour of a clear sky on a fine day 蓝色的: the blue lake 蓝色的湖 a dark blue dress 深蓝色的连衣裙 2informal sad 【非正式】 忧郁的,沮丧的: I've been feeling kind of blue lately. 最近我一直感到沮丧。 3 blue joke/movie a joke or film about sex 色情笑话/电影 → see also 另见 once in a blue moon (ONCE¹)