vi (1)打哈欠(open the mouth wide and take a breath when tired or bored)[I]：～and fall asleep 打哈欠继而入睡;She～ed all during his lecture.他讲演时她一直在打哈欠。He～ed widely.他张大嘴打着哈欠。

(2)裂(豁)开(open wide)[I][不用 prog]：The hole/A wide gorge～ed open in front of us (beneath our feet). 那个洞/一条宽阔的峡谷出现在我们眼前(脚下)。a～ing chasm/crack 一个张着大口的深渊/裂缝;a～ing gap between the rich and poor in society(fig)社会上富贫之间的巨大差别;

n (1)哈欠(deep usu involuntary intake of breath through the wide open mouth)[C]：He gave a～of sheer boredom.他打了个哈欠，感到十分厌倦。His～s suggested he was tired and bored.他打了好几个哈欠，表明他又累又烦。

(2)烦人的事或人(boring thing or person)[C，通常sing](infml)：He thought the cathedral a big～.他一想到大教堂就烦。(meeting/lecture) be one big～from start to finish (会议/讲座)始终枯燥无味;

→′yawnful adj 乏味的