adj (1)(中)空的(having an empty space inside;not solid)：a～ball/tube/tin/container 中空的球/空心管子/空罐头/空容器;an old～tree trunk 空的老树干;The pillars/chocolate eggs are all～. 柱子/巧克力球都是空心的。〖同〗empty; 〖反〗solid，filled;

(2)凹的，凹陷的(sunken;deeply set)：a～face/basin/dish 消瘦的脸/很深的水盆/深的盘子;～eyes/cheeks 凹陷的双眼/颊;be～eyed from lack of sleep 由于睡眠不足而两眼凹陷;a～cheeked man一个双颊凹陷的人;His cheeks are～.他的双颊深陷。

(3)(声音)空洞，(重浊)的(sounding as if made by，or in sth hollow)[通常作attrib]：～footsteps 沉闷的脚步声;give a～groan/echo/sound 发出低沉的呻吟/空洞的回音/嗡嗡的声响;have a～voice 发出空洞的声音;His voice was～.他的声音空空的。

(4) 1)虚假(的)(unreal;insincere;false)(fig)：make a～promise/truce/laugh 作出虚假的许诺/假意停战/发出虚伪的笑声;～laughter/sympathy/words虚伪的笑声/同情/话;His words/The accusations rang～. 他的话/那些指责听起来是虚假的。2)无真正价值的，无用的(worthless;not proving to have any value)：～arguments/joys/pleasures 毫无价值的争辩/空喜欢/白高兴;leave sb with a～feeling inside 给某人内心留下空落落的感觉;win a～victory 获得无真正价值的胜利;His independence/outward optimism/victory was(proved)～. 他的独立/表面的乐观/胜利是(证明是)毫无意义的。

→′hollowly adv 空洞地;虚伪地;′hollowness n 凹陷;空洞;

n (1)凹陷地，(尤指)小山谷(area，esp in the ground，that is lower than the rest，esp a small valley)[C]：hide in a～藏在小山谷里;have a picnic down in the～在这块洼地里野餐;The cottage was in a～. 那房子在一个小山谷里。a wooded～树木丛生的山谷;The ground was covered in little～s. 地面上布满了小坑。

(2)洞，坑，凹陷处(empty space within anything;a hole，depression)[C]：～s in sb's cheeks 脸颊上的小坑;hold a small bird in the～of one's hand 手掌心里托着一只小鸟;〖同〗depression，hole;

vt 挖空(take out the contents of sth in order to make it hollow)[T+n，T+n+adv(out)]：～out a log/pumpkin 把一根原木/一个南瓜挖空;dams～ed out by rushing water 被流水冲击而凹陷的大坝;

hollow out (v adv)挖洞做成(vt)：～out a canoe out of a log 把木头挖空做独木舟;～out a nest in a tree trunk 在树干上营巢